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BUILDING ENCLOSURE IN HONG KONG

BUILDING ENCLOSURE IN HONG KONG Wong Wah Sang

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Hong Kong University Press 14/F Hing Wai Centre 7 Tin Wan Praya Road Aberdeen, Hong Kong © Hong Kong University Press 1998 ISBN 962 209 449 X

All rights reserved. No portion of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopy, recording, or any information storage or retrieval system, without permission in writing from the publisher.

Printed in Hong Kong by United League Graphic & Printing Co., Ltd.

CONTENTS Foreword by Professor Eric K.C. Lye

vii

Preface

viii

Acknowledgements

ix

Part I: Introduction 1. Enclosures for Buildings in Hong Kong

1

Part II: Hong Kong Case Studies Environmental Issues 2. Verbena Heights 3. Hong Kong Technical College (Tsing Yi) 4. Public Toilet at Ngong Ping

9 25 35

5. The New Peng Chau Market

45

Small Building Design 6. Maple Garden Phase 3

55

Cladding and Glass Wall 7. The Peninsula Hotel Extension

65

8. The Administration Building at Lantau Island Crossing

79

Curtain Wall 9. The Lee Gardens 10. The Centre 11. Titus Square

91 105 115

v

Building Enclosure in Hong Kong

Creative Expression 12. The British Consulate-General 13. The Peak Tower

125 139

14. St. Thomas the Apostle Church

153

Local Technology 15. Bishop Lei International House

163

Advanced Technology Expression 16. The New KCRC Station 17. The Hong Kong Stadium

173 187

18. The Hong Kong Coliseum

201

Prefabrication and Standardization 19. HauTak Estate

207

20. Sheung Tak Estate

217

Sophistication of Design 21. Hong Kong Convention and Exhibition Centre Extension Bibliography

VI

225 245

FOREWORD This publication is a significant first step in dealing with the problem of building enclosure in Hong Kong. The hot, humid climate usually creates many problems for enclosures, especially when air and water pollution affect the outer surface of buildings. This is often compounded in Hong Kong by condensation and poor exterior and interior maintenance. I am happy to see that a publication of this kind has appeared. I hope it sets a trend so that more technical feedback can help architects and clients become more aware of the technical as well as aesthetic issues relating to enclosures. I am less concerned with the outer appearance of the enclosure as this is largely a matter of cost and personal preferences. The appropriate use of materials and their consequences is another factor that needs further investigation. For now, this book is an exceptionally good beginning.

Eric K.C. Lye Chair Professor Department of Architecture The University of Hong Kong

View of Hong Kong Central from Victoria Harbour.

PREFACE This edition of Building Enclosure in Hong Kong is intended as an educational tool for students of architecture or construction as well as an academic exchange of practice methodology for fellow professionals. The aim is to contribute to the advancement of architecture through education and practice. The importance of the building enclosure as an expression of the building form and functions is equal to that of the plan. Materials form components. Components form the building envelope. Performance of the materials influences various aspects of the enclosure including appearance, use and maintenance. What also matters is the way to assemble these material parts as details. The case studies present 20 buildings from Hong Kong ranging from small houses to large projects by local and foreign architects. In some cases, technology is used to express symbolism or human advancement. In other cases environmental concerns have been raised by architects and into the design of the enclosure. Curtain wall and cladding continue to be used in Hong Kong for commercial and institutional buildings to varied effect. A splendid palette of examples can thus be seen in the enclosures for buildings in Hong Kong. Continued development is expected in the search for design excellence and sustainability.

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ACKNOWLEDGEMENTS The author is grateful to the following architectural firms for their assistance and permission to use their drawings in the case studies: All Arts Limited; Anthony Ng Architects Ltd.; Architectural Services Department; Dennis Lau & Ng Chun Man Architects & Engineers (HK) Ltd.; Foster Asia (Hong Kong) Ltd.; The Hong Kong Housing Authority; HOK International (Asia/Pacific) Ltd., Hong Kong; P & T Architects & Engineers Ltd.; Rocco Design Ltd.; Terry Farrell & Partners; and Wong & Ouyang (HK) Ltd. (with S.O.M.). In particular, the author would like to thank Mr W.H. Lam, Mr S.H. Ha and Mr K.B. Fung of Wong & Ouyang; Mr Rocco Yim and Mr Hector Cheung of Rocco Design Ltd.; Mr Donald Choi and Miss Holyoak of Foster Asia; Mr Steven Smith of Terry Farrell; Mr Ernest Cirangle and Mr Julian KerrellVaughan of HOK; Mr Dennis Lau of L & N; Mr Stephen Poon and Mr Choi of the Housing Authority, Mr Anthony Ng and Mr K.S. Wong of Anthony Ng Architects; Mr S.H. Pau, Mr Macbeth and Mr Mau of ASD as well as Mr Bernard Lim and Mr Martin Fung of P & T. The author would also like to thank the British Trade Commision Hong Kong for their permission to publish photographs of the British Consulate, and The Hong Kong and Shanghai Hotels Limited, for their permission to publish photographs of the Peak Tower. A lot of people have contributed to the making of this book. Many thanks are due to Mr Yu Ying Sang for proofreading the manuscript, Miss Daisy Lau So Man for typing the manuscript, Mr Pang Yee Hang, Mr Curry Tse Ching Kan, Mr Chris Lam Po Wing, Mr Wong Kai Ming, Mr Wong Wan Cheung, Miss Angela Lee Lap Chi, Mr Keith Kung Chi Ming, Mr Michael Yen Koon Wai, Mr Albert Yiu Chi Wai and Mr Thomas Yuen Ka Yiu for drafting the axonometrics. Figures 4.3, 5.9, 8.6, 8.7, 9.1, 9.2, 10.2, 12.2, 12.3, 13.3, 13.4, 13.5, 18.1, and 18.2 were created by ArchiCAD®. Finally, the author gratefully acknowledges all the professional consultants, clients and contractors involved in the case study projects for their efforts and contribution to the advancement of architecture in Hong Kong.

The New KCRC Station is a glass pavilion giving openness to the interior space.

ENCLOSURES FOR BUILDINGS IN HONG KONG What is the enclosure of a building? Le Corbusier wrote: 'A mass is enveloped in its surface, a surface which is divided up according to the directing and generating lines of the mass; and this gives the mass its individuality'. The enclosure is the building skin or envelope covering the building mass and forming the building elevation or facade. Creation and order are the directing and generating lines from the building mass which means the plan in three-dimensional form and space. The enclosure gives the architectural expression which is unique to the building mass. THE FUNCTIONS OF THE ENCLOSURE The building enclosure has the following functions: 1. to act as a protective shelter for its inhabitants against wind and rain as well as fire hazards. 2. to control the influence of the external environment like solar heat, light, air and noise on the interior space, thus providing comfort. 3. to allow for the installation of building services and integration of the structure if necessary. 4. to give an external appearance to the building. The basic function of the building enclosure is to provide shelter. In Hong Kong, providing shelter against typhoon and rain is not an easy task. Water leakage is a common problem in buildings in Hong Kong. When water is driven by wind, it is pressed into the building from all possible directions. The building has to stand against both water penetration and wind load. So waterproofing has to be done cautiously and structure design has to take into acount various forms of loading. The shelter also needs to take account of various forms of movement due to wind expansion and contraction, and settlement of ground. Earthquake is not a factor to be considered in Hong Kong.

1

Building Enclosure in Hong Kong

Protection of inhabitants against fire is a function of building enclosure. Spread of fire can be a horror, even in modern times. The building enclosure should be able to stop or slow down the spread of fire whether from within or outside. Materials for construction are tested and classified according to various fire resisting periods to form construction components so that sufficient time is given to the inhabitants to escape from a building on fire before the components fail and collapse. In this respect, the internal planning and details of individual space will matter, in addition to the various provisions/details required by the building enclosure. Another function of the building enclosure is to separate the external environment and to contain an internal controlled environment suitable for various human activities. We expect the external environment to vary but the internal environment to be constant or varied within a certain range. Comfort is attained when a stable internal environment is attained. What we ask for is a controlled condition with moderate temperature, adequate light, pleasant humidity, smooth air circulation and a certain degree of quietness. All are simple demands but not easy to achieve. Therefore, the building enclosure can contribute positively to provide a comfortable interior, designed together with building services which means artificial lighting and mechanical ventilation. Structure and/or building services are sometimes incorporated into the design of the building enclosure. This means a total integration of the different building systems in the external wall. In the relationship between structure and external wall, there are three options: 1. Structure totally inside the building — in this case, the external wall is a simple skin and can be very light and elegant. 2. Structure forming part of the external wall — in this case, the structure is expressed as an integral part of building appearance and the external wall consists of infill panels. 3. Structure distinct from the outside of the building — this case is similar to the first one in having two separate systems for the structure and external wall. The external wall is self-supporting and appears light beneath a layer of the building structure. Different appearances and spatial experiences are created in these three options. Building services can also be classified similarly. When mechanical services are put outside the building, they can produce a striking impact.

Plate 1.2 The unique form of the Peak Tower enclosure identifies the building as a landmark in Hong Kong.

2

Enclosures for Buildings in Hong Kong

Building services are usually connected to the external wall. These services include the air intake and discharge of mechanical ventilation system, the fire service inlets and other services' inlets, the observation lifts, lighting protection systems, external lighting, and fire alarms as well as forms of service mechanisms for environmental control. The function of the enclosure to give the building a certain appearance is mostly attended to by the designers, the building owner as well as plain observers. Here the designer's ideas are consolidated and conveyed to people. Whether the building expresses culture, technology, environment or sheer engineering, it is the result of the efforts of many people acting both directly and indirectly. Some clients may like to have a building of prestige and they dictate styles for the designer to conform to. Only a good match of designer and client can produce good buildings. MATERIALS AND COMPONENTS Materials for enclosures include glass, metal, paint, natural stones, tiles, concrete and timber. The choice of material depends on the appropriateness of their performance characteristics in the particular situation. Such performance criteria are considered in the light structural serviceability, safety, habitability, durability, compatibility and aesthetics. Materials also combine to form building components making up the construction of the external wall. When components meet each other, joints are formed between different components. Special attention to these areas can produce good detailing in respect to function and aesthetics. Points to be considered as regards detailing are: 1. How components are constructed and put into other parts of the building 2. Joints to be adequate for structure (self-supporting or supported by other systems) 3. Joints to be watertight and drainage to be provided 4. Actual operation procedure 5. Maintenance problems and method 6. Appearance of the component in relation to other building parts 7. Environmental benefits such as reducing heat gain to interior, enhancing ventilation, using low embodied energy and recycling of materials or component parts Components of the enclosure include glazing, windows, roofing, parapets, skylights, walls, doors, balconies, canopies, shop fronts and other projecting features.

Plate 1.3 Maple Garden has a simple shelter of reinforced concrete.

3

Building Enclosure in Hong Kong

DESIGNING THE ENCLOSURE The enclosure is designed to meet the functional requirement based on the performance criteria of the materials and components. To act as a basic shelter, reinforced concrete wall is commonly used in Hong Kong. A thickness of 100 mm gives a minimum guarantee of waterproofing. This 100 mm thickness will not function if workmanship is poor with voids and 'honeycomb' defects. Increased thickness gives better sheltering effect but decreases the valuable net usable floor area of the interior. Cement sand rendering on the external surface enhances the sheltering function. The concrete surface is applied with a coat of spatterdash before cement sand rendering. When tiles are added on the rendering or using adhesive, movement joints have to be introduced to allow for various types of building movement. Glass walls in the form of curtain wall or window wall can provide shelter. Joints between the glass and metal frames are filled up with elastic sealants to provide adhesion as well as certain degree of movement. Frames in the curtain in wall have to allow for drainage of any water seeping in. Openable windows are provided with neoprene gaskets. Gaps between the structural opening and window frames are grouted to provide a water seal. Large glazing is suspended by hangers. Tests can be carried out on glazing or window mockups to ascertain strength. Metal cladding is also completed with sealants for waterproofing and movement. Joints are designed by calculation of the thermal expansion coefficient with the temperature range as well as possible deflection of the building. Stone cladding is dry mounted and similarly sealed but waterproofing usually relies on a protective layer that is applied to the concrete surface.

Plate 1.4 Metal cladding for the roof decking of the Lantau Toll Plaza.

Checklist for specifying curtain wall and cladding: 1.

Scope of works to include design, supply, delivery, storage, erection, connection, testing and maintenance 2. Preparation of shop drawings and dimensional co-ordination 3. Design warranty for performance period 4. Structural requirements for deadloads, live loads and wind loads as well as differential movements

4

Enclosures for Buildings in Hong Kong

Plate 1.5 Sunshades for solar control at Verbena Heights.

5. Performance requirements for overall thermal transfer values, thermal expansion, moisture resistance, water penetration, safety, acoustics, condensation, fire resistance, distortion free and low maintenance 6. Tolerances for manufacture and installation 7. General materials and workmanship including glass, coatings, metal panels, doors, fixing, joints, gaskets, sealants, lighting protection and earth bonding 8. Durable finishes 9. Samples and testing 10. Maintenance and repair To allow for environmental control, an insulated air gap will be effective for thermal and noise purposes when used on the curtain wall or claddings. Increased thickness of the concrete wall does help to achieve better insulation values. But sunshading devices or screens can be added on the external wall for effective solar control. Louvres are useful for ventilation purposes. Acoustical louvres can cut off machine room noise and help ventilation. Designing the building enclosure has to follow the Building Regulations and the Fire Services Requirements. These cover: 1. Structural adequacy 2. Objects to be prevented from falling 3. Fire safety with adequate fire resisting period and compartmentation 4. Limitation of openings near adjoining sites 5. Overall Thermal Transfer Value requirement 6. Means of Escape Code The external appearance of the building can be a result of the above considerations. A pattern of repeated components can give discipline and order to an elevation. An irrational approach can produce very artistic impressions. Elevations that can withstand the test of time usually blend in with the surroundings or become inseparable from the site context. This becomes culture in physical form. Environmentally friendly buildings can be of sustainable designs passing on to future generations. Good detailing for the enclosure will give buildings life and interaction with people.

5

Building Enclosure in Hong Kong

Table 1.1 Performance Characteristics of Materials and Components for External Wall in Hong Kong Material for Enclosure

Components formed by the Material

Structural Serviceability

Safety

Glass

— windows, glazing skylight

— framed support or structural sealant with glass buttresses — special glazing system available for large glass area, usually with suspension system — movement joint allowed around glass — tempered glass for better strength

— broken glass can be dangerous — laminated glass and tempered glass for safety — hired glass for fire rating — fire rated glass available

Metal (aluminium, copper, steel, stainless steel)

— w i n d o w frame, cladding, frame for glazing, roofing

— generally good structural strength — anchored to structural system of building — avoid common situation weakening structural strength

— secured installation is safe — steel with certain thickness can afford fire rating

Natural stones (granite, marble, sandstone, limestone, slate, travertine)

— cladding

— hung on concrete wall by steel anchors — normally heavy but can combine with expanded metal base to give lightweight panels

— insecure fixing causes falling hazards

Tiles

— wall finish

— stuck on wall by cement sand rendering or chemical adhesive which gives stronger but more flexible fixing — allow for movement joints

— insecure fixing also causes falling hazards

Concrete

— wall finish — insitu or precast as 'fair faced' concrete

— insitu concrete is intact with structure — precast concrete is mechanically fixed and sealed with grouting or insitu concreting

— good workmanship for insitu concrete especially on cantilevered structure for safety

Timber

— decorative wall finish as facing boards

— nailed or glued on concrete wall — not all timber can be used externally

— treatment to avoid fire hazards

Paint

— spray paint or rolled on paint as wall finishes

— adhere to background such as rendering concrete finishes

— some lead-based paint is poisonous — some paint can provide fire resistance

Enclosures for Buildings in Hong Kong

Table 1.2 Performance Characteristics of Materials and Components for External Wall in Hong Kong Material for Enclosure

Habitability

Durability

Compatibility

Aesthetics

— glass can withstand — reflective, — durable in normal transparent contact with most use or colour tinted material — coating and tint can — coating on glass can be worn off be degraded through especially during contact with some construction chemicals

Glass

— transmit heat and light when clear, absorptive when tinted, reflective when coated with various chemicals — reflect sound — stops certain amount of noise, double glazing or double w i n d o w is insulative

Metal (aluminium, copper, steel, stainless steel)

— durable in most — different metals — waterproofing at cases cannot be placed joints is achieved by — oxidation for metals together due to sealants is possible and may galvanic action — insulative materials resent to form a can be added for protective layer or control heat or corrode sound — fainting of colouring for certain coating

— anodizing gives colour to aluminium — paint, fluorocarbon coating, power coating and enamel coating can be applied to produce colours and pattern — texture can be made by engraving, embossing, etching, grinding or hammering

Natural stones (granite, marble, sandstone, limestone, slate, travertine)

— low conductivity, combines with air gap to give insulation — joints completed with sealant and background applied with waterproofing

— some stones tend to retain water and should be installed to allow water to dry up and avoid prolonged contact with water

— surface treatment can be polished, honed or flamed — range of natural colours available

Tiles

— not contribute much — durable for insulation — metallic surface — metallic tiles can more easily worn reflect solar down radiation

— no problem except for special coating surface

— wide range of colours available, glazed or unglazed — corner tiles and special shaped tiles available

— durable for most stones — sandstone and limestone more susceptible to wear and tear

Continued on p. 8

Building Enclosure in Hong Kong

Table 1.2 continued Material for Enclosure

8

Habitability

Durability

Compatibility

Aesthetics

Concrete

— generally good — durable — ingredients and insulator — surface can be water have to be — increase in thickness protected by paint 'clean' to avoid to improve insulation — rendering can be contamination, applied for which may cause protection but it nesting to steel changes the natural reinforcement appearance

— fairface concrete can take up texture of formwork — colour paints can be applied

Timber

— treatment to stop termite and insert growth

— colour fading under — no problem use — paint protection

— more natural

Paint

— some products can be heat/light reflective

— depends on product — re-application of paints may be required after certain period

— wide range of texture and colour — stone-like effects available — degree of glossiness available

— some products specify the preparation of the base before application

Plate 2.1 Verbena Heights as viewed from Po Hong Road.

VERBENA HEIGHTS Architectural

Firm: Anthony

Ng Architects

Ltd.

GENERAL This is a case study of a high-rise housing design demonstrating different design strategies for dealing with environmental problems. The basic technique is not using sophisticated high-tech expensive products but common local construction technology to achieve environmental benefits by careful planning and detailing. However, not all the design strategies have been implemented in the final construction due to other considerations. This design has already indicated an environmental concern. It is envisaged that more promotion and education on environmental protection issues will be necessary to sustain the man-made environment in Hong Kong. LOCATION This project is in the new town of Tseung Kwan O. The site is within an area of residential buildings newly developed or under development by private developers or the government. A highway lies on one side, causing noise problems for the high-rise flats. This project will house 1894 saleable apartments and 971 rental units. ENCLOSURE The enclosure design alone will not be sufficient to deal with environmental issues. This project consists of a group of building blocks orientated to capture prevailing wind for cooling in summer. To make this possible, wind tunnel studies are made on the building model to obtain

the best disposition of the building blocks for optimum natural ventilation. Some big openings are left in the blocks to affect the wind flow. In addition, the floor design on a linear layout gives better opportunities for cross ventilation. With such an environmentally positive layout, the building enclosure is considered to further enhance environmental protection. Basically the building wall is a conventional reinforced concrete wall with bay windows. An external shading device in the form of a concrete grid is installed as inter-block shading will not be sufficient. These sunshading screens also serve to block off part of the traffic noise. Solar effects and noise effects have been studied through computer modelling. In order to effectively use energy as well as to save the valuable internal space in this high density development, solar heat is also used for external clothes drying. So natural anodized aluminium perforated panels are added in front of the drying racks as screens. COMMENTS Design strategies showing concern for the environment is a matter of design attitude. The increase in construction costs usually is only a few percent but this will save much on future costs. The devices to save and use energy as demonstrated in this case study are not new inventions. What is important are the affectionate thoughts and caring attitude in working out a scheme that shows the possibilities beyond an otherwise conventional design.

9

Building Enclosure in Hong Kong

Figure 2.1 Layout at the third floor showing saleable blocks at the north and rental blocks at the south. Ventilation 'holes' are left to create aesthetical interest.

Architect: Anthony Ng Architects Ltd. Project Location: Po Hong Road, Mau Tai Road, Area 19B, Tseung Kwan 0, T.K.O.T.L. No. 35 Materials for Enclosure: Reinforced concrete structure, ceramic tiles, aluminium framed windows, reinforced concrete screen walls Completion: Scheduled at 1997

10

Verbena Heights

Plate 2.2 The completed central block from Po Hong Road - - scale of the high-rise blocks is broken down by varying heights of the block.

11

Building Enclosure in Hong Kong

ENERGY

ALTERNATIVE •Building layout designed to harness ambient wind for space cooling

NATURAL VENTILATION

•Wind tunnel studies to optimize wind-driven ventilation for apartment units • --

SOLAR SHADING / INSULATION

*External shading device and roof shading/ insulation to control heat gain

•Computer modeling analysis to optimize shading/daylighting design

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HARNESSING OF SOLAR ENERGY (ACTIVE)

•Provision designed for apartment units to incorporate solar water heating system

HARNESSING OF SOLAR ENERGY (PASSIVE)

•Clothes drying space with good solar/wind exposure to encourage use

•Light-shelves to optimize daylighting to depth of room; daylighting to lobbies and other communal areas

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Building integrated solar collector for water heating and photovoltaics for lighting, etc.

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Ventilation stack designed to utilize solar heating to drive air movement

5

Daylighting design integrated with intelligent control systems and photo/occupancy sensors

^Strategies executed or partially executed in Verbena Heights

Figure 2.2 Matrix of strategies towards sustainable housing design — energy aspects.

MATERIALS TROPICAL WOODS CONSERVATION

ALTERNATIVE

ADVANCE!

•Alternative formwork materials (e.g., steel, plastic, softwoods) to be used instead of unlabelled tropical woods

Standardization of design & efficient construction system (e.g., components prefabrication) to optimize use of form work materials

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MATERIALS REDUCTION

•Alternative wood products to be specified (e.g., MDF board for cabinets; engineered wood for structure)

Certified wood materials/products from managed plantation source to be specified

•Materials of durability matching expected service life to be selected (e.g., terrazzo floor tiling, Chinese granite paving)

•Space designed to have increased flexibility for the ease of future adaptations (e.g., convertible housing units)

SUSTAINABLY ACQUIRED.OR RENEWABLE RESOURCE

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•Materials with low embodied energy (e.g., some local products) to be specified where appropriate

RECYCLED CONTENT/ RECYCLABILITY

•Products with recycled content to be used where appropriate (e.g., play equipment using recycled aluminum/plastics)

Life-cycle energy use (initial/recurring embodied energy and operating energy) in building to be assessed

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iv> V ^Strategies executed or partially executed in Verbena Heights

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Figure 2.3 Matrix of strategies towards sustainable housing design — materials aspects.

RECYCLED CONTENT

RE-USEABIE, SALVAGEABLE

RECYCLABLE

Building design to be targeted with increasing % of recycled materials and recyclable or re-usable materials/ components

Building Enclosure in Hong Kong

LIVABILITY NOISE MITIGATION

PEDESTRIAN LEVEL WIND CONTROL

ADVANCED

ALTERNATIVE

Acoustic model tests to develop facade-mounted noise mitigation devices

•Block layout and noise barrier walls designed to reduce flats exposed to excessive traffic/ mechanical noise

•High- and low-rise blocks juxtaposed to reduce adverse wind impact on pedestrian area

•Wind tunnel modeling studies to optimize building design to safeguard pedestrian comfort & safety

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INDOOR AIR QUALITY

•Typical floor lobbies/corridors and car parking space designed to promote natural ventilation

Paints of VOCs and other materials containing "toxic" substances (e.g., adhesives) to be avoided for indoor application

URBAN GREENERY

•Communal planting space extended to upper levels for increasing amount of urban greenery

Integrated facade design (an "environmental filter") adapted for planting, solar shading, noise mitigation, etc.

^Strategies executed or partially executed in Verbena Heights

Figure 2.4 Matrix of strategies towards sustainable housing design — livability aspects.

Verbena Heights

1. cruciform plan (conventional)

2. 'linear' plan (saleable flats, Verbena Heights)

3. 'linear' plan (rental flats, Verbena Heights)

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Typical floor plans: cruciform vs. 'linear' forms adopted in Verbena Heights Figure 2.5 Lighting and cross ventilation is created by openings along the corridor.

15

Building Enclosure in Hong Kong

Plate 2.3 View of Verbena Heights — sunscreens and roof screens create environmental and aesthetic values.

16

Verbena Heights

Plate 2.4 View of Verbena Heights — an assembly of architectonics from environmental features.

Building Enclosure in Hong Kong

50 x 100 ceramic tiles 8 wide groove w/sealant pointing external plaster w/finishes Part elevation of rental block

A unit type 3P2 50 x 100 ceramic tiles 50 x 50 x 100 corner ceramic tiles

Part plan of rental block

Figure 2.6 Part elevation of a rental block.

18

Verbena Heights

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Plate 2.5 Roof feature and vertical fin at a rental block.

i Plate 2.6 Interior view of the bay w i n d o w and screen wall.

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4 . ;> 1. 175 x 650 RC beam in spray paint finish on fairface concrete as wall colour 2. RC screen wall in colour B (rough dotto) wall paint finish for rental block and colour A (rough dotto) for saleable block

Figure 2.7 Detail section of R.C. screen wall.

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Plate 2.7 R.C. screen wall in paint finish on facade of the bay window.

Building Enclosure in Hong Kong

Plate 2.8 R.C. screen wall on the bay w i n d o w facade.

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Figure 2.8 Elevation of R.C. screen wall.

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1. RC beam behind 2. RC screen wall in colour B (rough dotto) wall paint finish for rental block and colour A (rough dotto) for saleable block 3. setting out point for openings (vertical)

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Elevation of R.C. screen wai

Verbena Heights

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Drying racks of aluminium panel screen supported by stainless steel pipe.

Figure 2.9 The drying rack detail of a rental block.

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! Typical screen side elevation for drying rack (for rental block only)

Typical fixing detail of screen 1:4

1. 3 mm thick aluminium perforated panel w/natural colour anodized finish drying rack 2. drying rack 3. 380 S/S pipe hairline finish 4. 140 x 100 x 4.5 thick M/S plate cast-in to RC wall by fastener 5. 320 M/S pipe welded to M/S plate 6. 3 mm thick aluminium perforated panel w/natural colour anodized finish

21

Building Enclosure in Hong Kong

Plate 2.10 View of Verbena Heights — the monotony of typical flats is offset by the varied use of sunscreens.

22

Verbena Heights

Figure 2.10 Isometric of wall section with sunscreens.

175x650 R.C. beam

aluminium window

aluminium bay window

23

Plate 3.1 Aluminium sunscreens are used for solar control. Metallic glazed tiles reflect excessive heat.

HONG KONG TECHNICAL COLLEGE (TSING YI) Architectural

Firm: P & T Architects

& Engineers

Ltd.

GENERAL

ENCLOSURE

This case study presents another project that exploits environmental techniques to construct an energy efficient building. Site planning and massing are the initial steps to consider for saving energy. Thus, the buildings are planned with the short sides facing east and west. Machinery rooms are placed on positions with strong sun. This reflects the planning for environmental control. The roof is an area with much solar exposure. In this project, landscape planting, water features and covered walkways are placed on the rooftop forming usable amenities as well as an insulating layer.

To limit the effect of the absorbed solar heat on the interior, deep recessed facades and sunshading fins are techniques used in the elevations' window design. Some windows are openable to allow natural ventilation when possible. The reinforced concrete external walls are covered with reflective metallic tiles to reduce solar heat gain. Windows are constructed of a grey tinted glass which absorbs some heat, thus reducing solar heat gain to the interior.

LOCATION

This project uses simple means but careful planning and design to achieve an energy efficient building. The overall thermal transfer value is of 10.27 w/m 2 performance, compared with general curtain wall buildings of 80 w/m2. Site planning, functional planning, circulation, wall design and selection of materials all contribute to the success of this project.

The site is a six-hectare site on Tsing Yi Island. It is a rather rural site with a hill as its backdrop. A highway lies on one side and a high-rise residential estate is nearby. The project takes advantage of natural resources and aims to capture the summer sea breeze by elevating the south side of the main building to facilitate natural ventilation.

COMMENTS

25

Building Enclosure in Hong Kong

Figure 3.1 The diagrams here illustrate environmental concepts — the planning of the site, design of elevation and selection of materials all contribute to energy efficiency.

Main Sjtaircore

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Sea Breeze fk>m thej South East direction

CONCOURSE LEV,EL

Basic Teaching Wing

Natural Ventilated Courtyard

Orientation of Basic Teaching Wing

South Elevation

Architect: P & T Architects & Engineers Ltd. Project Location: Tsing Yi Road and Sai Shan Road, Tsing Yi Island Materials for Enclosure: Reinforced concrete frame, aluminium windows with grey t i n t e d glass, m e t a l l i c lustre reflective ceramic tiles, aluminium sunshading fins Completion: 1993

26

Sunshading Fins

Use of Waste A/C Air

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Room Depth and Cross Ventilation

Hong Kong Technical College (Tsing Yi)

Photo by courtesy of P & T Architects & Engineers Ltd.

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Plate 3.2 View of the Technical College — the rational character of the elevation is a reflection of modular planning.

27

Building Enclosure in Hong Kong

Plate 3.3 View of the bridge connection and deep overhang.

28

Hong Kong Technical College (Tsing Yi)

Plate 3.4 An overall view of the Technical College shows juxtaposition of blocks perpendicular to the linear site.

Photo by courtesy of P & T Architects Engineers Ltd. Plate 3.5 The metallic industrial look of the entrance canopy reflects the technical character of the institution.

29

Building Enclosure in Hong Kong

Plate 3.6 Interior view of the sports hall — natural ventilation is made possible by installing remote-controlled louvres on the walls.

Photo by courtesy of P & T Architects Engineers Ltd. Plate 3.7 Interior view of the workshop.

30

Hong Kong Technical College (Tsing Yi)

Figure 3.2 Isometric showing the wall section with the sunshading device.

-aluminium window

-planter

335x75 mm -aluminium box section sun fin

600 x 600 mm R.C. sun fin

31

Building Enclosure in Hong Kong

Figure 3.3 Elevation of the main entrance.

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Plate 3.8 Roof garden with covered walkway.

32

Plate 3.9 Variation of sunshades on elevation.

Plate 3.10 The main entrance.

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Hong Kong Technical College (Tsing Yi)

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Plate 3.13 Natural ventilated courtyard.

33

Plate 4.1 View of the public toilet showing its rural setting.

PUBLIC TOILET AT NGONG PING Architectural

Firm: P & T Architects

& Engineers

GENERAL This is a small project using simple environmental strategies to enclose the building, allowing natural lighting and cross ventilation. The two blocks of public toilet demonstrate simplicity of the design and illustrate the possibilities for environmental control. LOCATION This is a rural site next to the Po Lin Monastery and the Buddha Statue on Lantau Island on Ngong Ping Road. In this location, vernacular principles are used to derive the building enclosure as well as to monitor the interior environment. ENCLOSURE This is a one-storey building; the design of the roof is therefore a major consideration for the building enclosure. To allow light penetration and natural ventilation, an elevated pitched roof is used. This creates

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an opening at high level allowing diffused lighting and natural cross ventilation. Air intake at low level is possible through grilled openings in the cubicles and on the external wall. Such devices create a simple stack effect for air movement. For construction materials, steel I-beams are used to support the elevated roof instead of traditional timber brackets. But clay tiles form the roof finish to provide the rural character. The external wall is finished with simple spray paint on rendering. Reinforced concrete columns are chiselled fairface concrete. Slate tiles form the finish for the dado. A natural look is achieved using simple materials. COMMENTS A small project can exploit grand concepts. This simple building illustrates that the concept of environmental design can be incorporated into the building enclosure. The building is integrated with the natural process to create harmony between humankind and nature.

35

Building Enclosure in Hong Kong

^**ABMJ£.w Plate 4.2 Exterior view of the roof and wall construction.

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Plate 4.3 A view from Ngong Ping Road illustrating its vernacular character.

Plate 4.4 Interior view of the toilet — a pleasant and neat appearance is created.

37

Building Enclosure in Hong Kong

Plate 4.5 Exterior view showing its vernacular character.

38

Public Toilet at Ngong Ping

Figure 4.1 Diagrams illustrating environmental s t r a t e g i e s — n a t u r a l l i g h t i n g and ventilation are incorporated through a single design method.

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ventilation concept

diffused light

T^" lighting concept

Architect: P & T Architects & Engineers Ltd. Project Location: Ngong Ping Road, Lantau Island Building Enclosure: Steel structure, chiselled finished fairface concrete for the columns, slate and spray paint for walls Completion: 1995

39

Building Enclosure in Hong Kong

Figure 4.2 Layout plan showing the toilet blocks staggered to achieve good ventilation.

40

Public Toilet at Ngong Ping

Figure 4.3 Isometric of wall section showing simple construction for environmental concern.

41

Building Enclosure in Hong Kong

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

powder coated alum, fins stucco finish in-fill panel fairface concrete chiselled finish S.S. grille gate G.M.S. roof bracket system roofing tiles powder coated alum, lattice 12 mm thick tempered stained glass panel 12 mm thick tinted tempered glass panel 12 mm thick tempered glass panel with etched pattern laid in S.S. frame

Figure 4.4 Elevations.

42

11. G.M.S. bracket system painted 12. 100 mm S.Q. C.I. rainwater spout 13. fairface concrete chiselled finish 14. powder coated alum, lattice 15. 25 mm 0 S.S. rod fixed to G.M.S. bracket system 16. 10 mm thick tinted tempered glass panel laid in S.S. frame 17. G.M.S. planter box framed with timber lattice structure 18. roofing tiles 19. louvre detail 20. fairface concrete chiselled finished

Public Toilet at Ngong Ping

1. G.M.S. bracket system painted 2. 100 mm S.Q. C.I. rainwater spout 3. fairface concrete chiselled finish 4. G.M.S. roof bracket system painted 5. roofing tiles as specified 6. powder coated alum, fins 7. fairface concrete chiselled finish 8. S.S. grille gate 9. roof tile 10. powder coated alum, fins 11. powder coated alum, louvre 12. G.M.S. planter box framed with timber lattice structure 13. finish expansion joint 14. louvre detail

Figure 4.5 Elevations.

Figure 5.1 Elevation of the main entrance.

THE NEW PENG CHAU MARKET Architectural

Firm: P & T Architects

& Engineers

GENERAL This is another case study of a building enclosure which focuses on environmental control. The project is a threestorey building housing the market stalls in the lower two levels. The machinery rooms are on the top floor. This offers a thermal insulation buffer against the solar heat gain on the roof. LOCATION The site is located on the outlying island of Peng Chau. With the last natural environment around the site, the project is designed to be environmental friendly. ENCLOSURE The building is mechanically ventilated but can also be naturally ventilated. This is facilitated by a mechanically operable louvre system within the external wall which can be used at night when the market is closed. The

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external wall is finished with spray paint and ceramic wall tiles. Fixing is by means of bonding agent to ensure a good contact for the concrete base. The columns are of fairfaced concrete structure finished with waterproof coating. The roof is designed with deep overhangs to shield off solar heat. A fibre glass cladding system is designed for the roof overhangs. The cover part of the building is designed to be finished with timber panels to give a natural appearance. Special varnish coats the timber to stop deterioration and insect growth. COMMENTS Again, careful planning makes a building different. With the budget and functions almost u n c h a n g e d , environmental consideration improves the energy efficiency of a building, making it more sustainable and c r e a t i n g h a r m o n y between its users and the environment.

45

Building Enclosure in Hong Kong

Figure 5.2 First floor plan at 8.65 m.p.d. / ^ J

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

meat stall wet goods dry goods switch room male toilet female toilet lift vegetable sorting area refuge collection office A.H.U. room store room escalator deck

Figure 5.3 Ground floor plan at 4.00 p.m.d.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10 11 12

fish poultry lift disabled's toilet plant room transformer room newspaper LP.G. store void refuge collection scalding room loading & unloading

Architect: P & T Architects & Engineers Ltd. Project Location: Wing On Street, Peng Chau Materials for Enclosure: Spray paint and ceramic tiles on reinforced concrete wall, fairfaced concrete nonwaterproof sealer on columns. Fibre glass cladding system and mineral coating system for the roof Completion: Scheduled for 1998.

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The New Peng Chau Market

Figure 5.4 Roof plan at 16.30 m.p.d.

Figure 5.5 Mezzanine floor plan at 12.45 m.p.d.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10 11 12 13

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Building Enclosure in Hong Kong

Plate 5.1 Model study for the building form and enclosure.

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The New Peng Chau Market

Figure 5.7 Sections showing deep overhangs for sunshading.

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Figure 13.1 The Peak Tower was conceived as a bowl flowing on the continuous Hong Kong skyline

THE PEAK TOWER Architectural

Firm: Terry Farrell & Partners

GENERAL This is a case study illustrating how the enclosure projects an i m p o r t a n t identity to the public. Construction technique and selection of materials enhance the contrast in building expression. This building also houses the tram terminal in the lower part of the building. The upper parts are restaurants and shops. LOCATION The site is a prominent location on the Peak forming part of the skyline of Hong Kong. To avoid a bulky building, the building is divided into two parts. The upper part is elevated and shaped like a bowl to give a floating effect. The lower part is more attached to the original landform and skyline. ENCLOSURE The 'bowl' shaped upper part is constructed of aluminium panel cladding and clear double glazing.

Double glazing is used to stop any condensation which might block the view. The lower base portion is of spray paint on rendering finish. These create a contrast with a more modern technology-based appearance for the top and a more solid and stable outlook for the bottom portion. The elevated 'bowl' has been conceived as an expression of local culture symbolizing an elevated rice bowl. It looks as if it is stretching out welcoming hands with its upturned eaves of traditional Chinese architecture. The lower portion gives the massive look of a wall rampart. To install floodlighting for the building, large 'lanterns' are constructed at the base of the building. Finishes for these features are ceramic tiles, translucent glazing and aluminium frames. COMMENTS Cultural expression can be given by the appropriate types of building technique, form and detailing. Contrast of technique within a building can produce designated highlights while it remains an integrated building.

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Building Enclosure in Hong Kong

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Plate 13.12 Glazing at the north elevation.

Plate 13.15 Glazing and cladding at the west elevation 'bowl'

Plate 13.13 View of the roof showing air conditioning plants and the gondola track.

Plate 13.16 Lantern and podium pillars finished in glazed tiles and spray paint.

147

Building Enclosure in Hong Kong

Plate 13.17 Open staircase finished in a thin concrete slab with glass panel balustrade for transparency and openness.

148

The Peak Tower

Figure 13.3 Isometric showing the construction of the lanterns at ground level.

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aluminium cladding

aluminium probing blades

natural anodized aluminium transom shear wa

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Building Enclosure in Hong Kong

Figure 13.4 Isometric of the wall section for the north elevation of 'bowl' cladding and glass wall.

1. 2. 3. 4. 5. 6. 7.

aluminium panel Translucent glazing S.S. bolt fitting to glass aluminium panel double glazed unit (clear) S.S. bolt fitting to glass S.S. spliceplate with S.S. cover plate (sandblasted finish) 8. S.S. coverplate (sandblasted finish) 9. aluminium panel 10. 10 mm deep recess

150

The Peak Tower

Figure 13.5 Isometric of the wall section for the south elevation of 'bowl' cladding and glass wall.

1. aluminium capping 2. aluminium panel 3. PVF2 aluminium weather louvres 4. aluminium louvres (special profile) 5. false ceiling 6. aluminium panel 7. vision panel (inward opening) 8. aluminium panel 9. 10 mm deep recess 10. aluminium panel

151

Plate 14.1 Model of the Church.

ST. THOMAS THE APOSTLE CHURCH Architectural Firm: Wong Wah Sang as Design Consultant with All Arts Limited

GENERAL

ENCLOSURE

Spiritual expression is another form of presentation for the building enclosure. Religion as a spiritual subject is transformed into a physical architecture. In other words, architecture becomes a frozen spiritual symbol. This case study is about a building addressing such spiritual issues in additon to functional and environmental issues.

The entrance to the building is abstracted from the asymmetrical Chinese word for door 'P^\ This marks the start of an axis from the exterior to the interior of the building, asymmetrical both at the interior and exterior. Brick tiles and fairfaced concrete are used to finish the building. These are chosen to give a solid feel of the material texture. Aluminium sunshades and recessed windows are used for solar control at the west elevation. Skylights are introduced to create a stack effect and cross ventilation for the church hall. Solar heat gain is thus controlled and energy efficiency is achieved.

LOCATION The site is at the new town of Tsing Yi Island amidst high-rise residential buildings. It is close to a park and a community centre with a bus terminus. The site is relatively open on the boundaries; the enclosure will thus be quite visible when constructed. The irregular five-sided shape of the site positively generates the plan and the elevations. Adjacent to a park, the north elevation of the church hall at the upper floor is designed with a glass wall for views in and out. This matches with the concept of a more open and inviting religion.

COMMENTS Functional, environmental and spiritual approaches can be integrated into the enclosure design and presented as an expressive image of a building. Sustainability in the sense of both physical and spiritual aspects can be realized by the concern for both aspects and transformed into building plans and elevations.

153

Building Enclosure in Hong Kong

Plate 14.2 View of the model — the north elevation with a glass wall for the church contrasts with the east elevation of a brick-tiled solid wall

154

St. Thomas the Apostle Church

Plate 14.3 Model of the church complex— the entrance, the skylight to the baptistry and the cross define an axis to the interior procession for the church.

155

Building Enclosure in Hong Kong

Plate 14.4 Model showing the north elevation with a glass wall expressing the open attitude of the church; the staggered windows are installed for movement of the staircase.

Plate 14.5 Study model of the interior of the Church showing the large glass wall.

56

St. Thomas the Apostle Church

Figure 14.1 Diagram showing further development of the skylight as v e n t i l a t o r to p r o v i d e n a t u r a l l i g h t i n g and stack effect for ventilation. Modification for the skylight to exceed site coverage limitation was accepted by the Building Authority in view of the environmental benefits.

heat accumulated and heat up the church hall interior by convention

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Architect: W o n g Wah Sang as D e s i g n Consultant with All Arts Limited Project Location: T.Y.T.L. no. 133, Tsing Luk Street, Tsing Yi Materials for Enclosure: Brick tiles and fairfaced concrete walls, tinted glass and anodized aluminium frame for w i n d o w s , clear glass for glass wall, tempered glass for skylight Completion: 1988

157

Building Enclosure in Hong Kong

NON-EXCLUSIVE RIGHT OF WAY (BROWN AREA)

Figure 14.2 The west elevation showing the entrance to the church.

158

St. Thomas the Apostle Church

Figure 14.3 The north elevation showing the glass wall system.

159

Building Enclosure in Hong Kong

Figure 14.4 Isometric of the skylight system over the baptistry.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10 11

160

tempered grey tinted glass panel aluminium cladding tempered grey tinted glass panel tempered grey tinted glass fin fairface concrete finish side hung aluminium window external wall tile finish tempered clear glass panel formwork joint entrance doorframe font

St. Thomas the Apostle Church

Figure 14.5 Isometric of the construction for the external wall.

1. inverted beam 2. S.S. circular section sunshading device 3. aluminium window 4. S.S. railing bar 5. external wall tile finish 6. R.C. projection 7. fairfaced concrete finish 8. aluminium cladding 9. top hung aluminium window 10. R.C. projection 11. recessed uplight 12. aluminium cladding 13. metal frame projection 14. suspended glass panel (tempered glass) 15. glass fin 16. sliding window 17. roller shutter 18. aluminium false ceiling 19. R.C. projection 20 surface U-channel

161

Figure 15.1 The east elevation has a lantern-like appearance with stonelike spray paint.

BISHOP LEI INTERNATIONAL HOUSE Architectural

Firm: Wong Wah Sang Architects

as Consultant

GENERAL This is a case study of a high-rise, 24-storey block. In addition, it has two semi-basements using conventional local building techniques to complete the external elevations. The difference lies in the exploitation of the plan form and feature details to make an otherwise standard hostel design a special building with its own identity. LOCATION Located within a large site adjacent to various properties owned by the Roman Catholic Church of Hong Kong, this building is intended to give a dialogue with the existing Cathedral of the Immaculate Conception on the site. Motifs and details of the old Cathedral are 'symbolized' into the building and these have become various functional parts. ENCLOSURE The east elevation facing the harbour develops from a staggered and symmetrical plan with an axis along the east-west direction. This layout allows a sort of corner window for the rooms extending the spatial feeling and allowing better view. Windows are designed in full height from ceiling to floor with green tinted glass and fluorocarbon-coated aluminium giving a look of curtain wall. This is achieved by recessing the structural beam from the building envelope to allow a 'shallow' appearance for the spandrel portion which is finished

with All Arts

Limited

with a green colour stone-like spray paint. The west elevation facing Robinson Road has limited views so the design of the enclosure is kept simple and focused on the entrance. An archway finished with granite marks both the vehicular and pedestrian entrance to the building. However, the focus of this elevation is a wall relief artwork at the central axis of the elevation. This is formed by using corner glazed tiles as a relief against the background of plain white glazed tiles (95 mm x 45 mm). The north and south elevations are finished with white glazed tiles. Adhesive is used for the installation base to provide flexibility and strong adhesion due to building movement. In this respect, movement joints are provided at every storey of the building. Details on the enclosure are abstracted from religious images from the Cathedral. For example, the metal grilles covering the air conditioners are made of aluminium bars, fluorocarbon coated in a green colour and designed in pattern of triangles and circles. The roof mast reflects the pinnacles on the existing Cathedral. The entrance archway is related to the Cathedral buttresses. COMMENTS These are numerous design opportunities created by using local conventional building techniques. This study illustrates how artwork can be combined with building functions and components. While the building does not obtrusively stand out from the surroundings, it retains an individual identity.

163

Building Enclosure in Hong Kong

Figure 15.2 Typical plan imposed on section showing guest rooms on the typical floor and the podium functions.

Architect: Wong Wah Sang as consultant with All Arts Limited Project Location: 4 Robinson Road, Mid-Levels, Hong Kong Materials for Enclosure: Reinforced concrete structure, green tinted glass with fluorocarbon-coated aluminium frames, stone-like spray paint, and white glazed tiles Completion: 1995

164

Bishop Lei International House

Plate 15.3 View of Bishop Lei International House from the north-east with the Catholic Church in the foreground — harmonizing with the environment is a key strategy in the elevation design.

165

Building Enclosure in Hong Kong

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Plate 15.4 View of the west elevation from Robinson Road — the facade is in a pattern of full-height glazing and window air-conditioning units.

166

Bishop Lei International House

Plate 15.5 View of the west elevation and part of the granite portal frame for the entrance.

167

Building Enclosure in Hong Kong

Plate 15.6 Night view- • floodlights light up the facade and the roof mast feature.

168

Bishop Lei International House

Plate 15.7 At the centre of the west elevation, corner tiles are used to build up a simple geometric pattern as a wall mural.

Plate 15.8 View of the podium and the granite portal frame for the entrance.

169

Building Enclosure in Hong Kong

Figure 15.3 Isometric of construction for the roof f e a t u r e . F i n i s h i n g is in a l u m i n i u m cladding.

—aluminium cladding to pinnacles

-Aluminium Cladding

Plate 15.9 View of the roof mast.

170

Bishop Lei International House

Figure 15.4 Isometric of the window construction.

1. 300 mm thick RC wall 2. platform for A/C outdoor unit 3. 100 mm thick RC wall 4. aluminium transom 5. pilmet board 6. metal louvres 7. false ceiling 8. moulding 9. carpet flooring

Plate 15.10 View of the f u l l - h e i g h t w i n d o w and aluminium grille-covered window unit at the east elevation.

Plate 15.11 Part view of the west elevation.

171

Plate 16.1 View of the wave roof under construction.

THE NEW KCRC STATION Architectural Firm: Foster Asia (Hong Kong) Ltd.

GENERAL This is a case study of the extension of the existing Hung Horn terminus of the Kowloon and Canton Railway, which takes the form of a simple rectangular glass pavilion that gives lightness and openness. LOCATION This site is on the roof deck of the railway station; a lightweight pavilion structure of steel and glass is therefore a suitable solution. The pavilion is supported by steel columns that distribute the structural load to a steel raft on the existing deck.

natural lighting. By using full-height glass walls, much energy required for lighting can be reduced. To supplement the skylight, artificial lights are incorporated to control the light intensity inside the pavilion. The wave roof also forms deep eaves to shade excessive solar heat from the pavilion. The steel wave roof is finished with metal decking and dense rigid mineral wool for insulation. The upper surface is finished with PVC waterproof membrane. The ceiling is constructed of perforated steel infill panels and eaves completed with aluminium panels. The glass walls are independent of the pavilion structure and stand on a structural grid of 3 m with an infill panel module of 3 m x 1.22 m. Clear toughened glass is used.

ENCLOSURE COMMENTS The enclosure aims to create a spacious, generous and well-lit interior by means of simplicity of layout. The rectangular layout is denoted by peripheral columns supporting steel torsion 'spire' beams which then hold the steel wave beams with profiled metal decking. The wave roof is used to incorporate skylights as

A simple, open design is always effective for large buildings intended for movement of people. Both aesthetic and environmental aspects of design are dealt with by the use of the simple wave roof in this pavilion building.

173

Building Enclosure in Hong Kong

Drawing by courtesy of Foster Asia

NORTH-SOUTH SECTION Plate 16.2 Diagram of the design concept showing lighting control of the concourse.

CAD by courtesy of Foster Asia

Architect: Foster Asia (Hong Kong) Ltd. Project Location: Cheong Wan Road, Kowloon Station, Kowloon Materials for Enclosure: Steel c o l u m n s + beams s u p p o r t i n g steel decks c o m p l e t e d w i t h mineral wool insulation + PVC finish, glass walls of steel frames and clear toughened glass. Completion: Under construction in 1997, scheduled completion in 1998

174

Plate 16.3 CAD of the exterior view of the pavillion.

Photo by courtesy of Foster Asia

Plate 16.4 Aerial view of the model showing the wave roof.

Photo by courtesy of Foster Asia

Plate 16.5 View of the model showing the interior and the roof of the pavilion.

Building Enclosure in Hong Kong

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Plate 16.6 View of the glass pavilion under construction.

176

The New KCRC Station

177

Building Enclosure in Hong Kong

Plate 16.7 Construction of the glass wall and wave roof — the glazing is set as an independent enclosure from the columns supporting the wave roof.

178

The New KCRC Station

Plate 16.8 View of the external glazing under construction.

Plate 16.9 View of the wave roof with roof lights and metal decking under construction.

179

Building Enclosure in Hong Kong

Plate 16.10 View of the joint for the column and wave beam — metal decking forms the basic roof enclosure.

180

The New KCRC Station

Figure 16.1 The wall and roof section cuts through the roof light which provides natural l i g h t i n g and is s u p p l e m e n t e d by artificial lighting.

1. perforated steel infill 'planks' with acoustic insulation 2. extruded aluminium louvres by lighting works contractor 3. skylight 4. cantilevered glazing 5. steel wave beam 6. steel torsion 'spine' beam 7. clerestory glazing 8. fabricated steel T section with tapered end 9. steel column 10 internal flooring 11 propiled metal decking 12 column cladding panel 13 decants rigo mineral wool insulation

181

Building Enclosure in Hong Kong

Figure 16.2 Part elevation of the corner of the building.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10

182

steel T section fascia roof steel work steel torsion 'spine' beam 160 x 70 aluminium channel extruded aluminium panel system with glazed infill 1500 x 1220 module steel column external paving sunshade clerestory glazing flexible movement gasket

The New KCRC Station

1. 2. 3. 4. 5. 6. 7.

drainage channel PVC waterproof membrane dense rigid mineral wool insulation profiled metal decking cantilevered glazing steel split wave beam skylight

8. fabricated steel fascia I section 9. extruded aluminum panel system with glass infill 10. fabricated steel I section with tapered end 11. steel column 12. peripheral channel 13. external paving 14. steel torsion spine beam

Figure 16.3 Isometric of the wai and roof construction.

183

Building Enclosure in Hong Kong

Plate 16.11 The wave beam anchored on the circular spine beam supported by columns.

184

The New KCRC Station

Plate 16.14

Plate 16.17

Plate 16.18

Plate 16.16 Plates 16.14-16 External view of the erection procedure of the roof structure and decking.

Plate 16.19 Plates 16.17-16.19 Internal view of the erection procedure of the roof structure and decking.

185

Figure 17.1 A three-dimensional study of the form of roof cover.

THE HONG KONG STADIUM Architectural

Firm: HOK Sports Facilities Group, Kansas City, Missouri, (Asia/Pacific) Ltd., Hong Kong

GENERAL This is a case study of a large span megastructure forming the fabric roof cover of the sports stadium. This stadium provides 40 000 seats surrounding an international-size football pitch. LOCATION The site is at the lower part of a valley with tall buildings close by and adjoining other sports field and facilities. The creation of excessive noise can pose environmental problems. ENCLOSURE With anchor points extending beyond the stadium, a pair of elegant arches span 240 m from the prime structure to answer the client's brief for unobstructed view. From these main arches, secondary trusses span to the rear wall of the upper terrace. The structure of the basic frame is a stiff pin supported portal frame and the terrace is formed as a reinforced concrete frame for spanning the secondary trusses to the main arches. The structural elements are basically circular hollow steel sections.

USA, and HOK

International

The roof surfacing is a fibre-reinforced Teflon fabric with a cable support system. This fabric is translucent under strong daylight or evening floodlights. Floodlights are installed on the main structural arch. About 300 metal halide floodlights of 1800 W are used to give an illumination of 1400 lux to the football pitch. This can be tuned down for various occasions. The general seating is lit up by other floodlights on the roof structure giving an illumination of 300 lux. The design of the acoustics mainly focuses on sports use and enhances the perception of the crowd noise without excess reverberation. The semi-open roof enclosure allows noise to escape from the stadium. Integrated with life safety and fire alarm systems, the sound system consists of satellite cluster type loudspeakers located underneath the front edge of the roof system. COMMENTS Structure and building services can be integrated into the building enclosure to produce an elegant design. This case study has been a formidable technical challenge representing an extraordinary design expression of an enclosure.

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Building Enclosure in Hong Kong

Figure 17.2 Layout plan for the Hong Kong Stadium.

Architect: HOK Sports Facilities Group, Kansas City, Missouri, USA and HOK International (Asia/Pacific) Ltd., Hong Kong Project Location: Eastern Hospital Road, Causeway Bay Materials for Enclosure: Fibre-reinforced Teflon fabric roof surface supported by steel arch and tension ties, reinforced concrete stadium Completion: 1995

188

1. office building roof below 2. ramps below 3. entry plaza below 4. insulated glass entry pyramid below 5. access road below 6. ramps below

The Hong Kong Stadium

Photo by courtesy of HOK

Plate 17.1 Study model of the stadium. Photo by courtesy of HOK

Plate 17.2 View of the stadium under construction.

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Building Enclosure in Hong Kong

Plate 17.3 Part view of the roof and seating — steel truss supports the Teflon sheeted roof as well as the lighting system.

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The Hong Kong Stadium

Plate 17.4 Part view of the stadium.

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I

: Plate 17.5 View of the Hong Kong Stadium set in a valley overlooking Causeway Bay and Victoria Harbour.

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The Hong Kong Stadium

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Building Enclosure in Hong Kong

•-tfasr^'' • Plate 17.6 View of the stadium from Eastern Hospital Road.

194

The Hong Kong Stadium

Photo by courtesy of HOK

Plate 17.7 Views of the stadium at night from Eastern Hospital Road showing the illumination system.

195

Building Enclosure in Hong Kong

Photo by courtesy of HOK

Plate 17.8 Night view of the lit-up stadium — seating is lit up at a level of 300 lux.

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Figure 17.3 Longitudiual building section looking east and transverse building section looking north of the preliminary scheme.

Building Enclosure in Hong Kong

Plate 17.9 Lighting mounted on the steel truss.

Plate 17.10 Joint of the roof system onto the top of seating.

Figure 17.4 Section through the stadium and office for the final design.

Plate 17.11 Pin point of steel truss anchored onto the ground.

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The Hong Kong Stadium

Plate 17.12 Back of the concrete finished seating.

1. precast steps 2. main beams cast to seating profile 3. precast terrace 4. precast terrace 5. new terrace seating (precast) 6. perforated pipe Figure 17.5 Section through the seating showing the structure concept.

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Plate 18.1 Part view of the coliseum on the railway station podium.

THE HONG KONG COLISEUM Architectural

Firm: Architectural

Services

Department

GENERAL This is a case study of a single enclosure which can house 15 000 people. Imaginative engineering skills are used to make the roof cover with the external part of the spectator stand as part of the building envelope. LOCATION The site is on the roof deck of the Hunghom railway station, therefore a heavy structure is not possible. Even during construction, heavy loading has to be avoided. The building is located at the middle of the roof deck with ample space surrounding it for circulation and dispersal of people. As the building is remote and usually operates in the evenings, there is little environmental problem regarding noise or energy. ENCLOSURE A space frame of 100 x 100 m is used as the roof structure. To construct this, the steel frame was built

on the ground and then raised to the roof position by four temporary supporting towers. This procedure is used to save the huge amount of scaffolding thus reducing the construction weight on the podium deck. Then a prestressing technique was used to construct the reinforced-concrete grandstand. This structure was then used to support the roof space frame. The roof space frame was covered by precast reinforced concrete panels with plastic sheets as a vapour barrier and foamed polystyrene sheets as insulation. A layer of reinforced concrete acts as a thick screening to finish the roof top. The slanting wall enclosure is formed by the spectator stand concrete wall. This is off-form concrete finished with paint. COMMENTS A bold statement to complete a large assembly building is effective in both functional and aesthetic aspects. The imaginative engineering is the determining design factor for the success of this enclosure.

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Building Enclosure in Hong Kong

Figure 18.1 Procedure for construction and erection of the roof truss. i. Steel roof trusses were assembled at the ground level. ii. Temporary supporting towers and working platforms were erected. iii. The roof structure was raised to the top. iv. The roof trusses then rested on the four supporting towers with additional bracing cables. v. C o n s t r u c t i o n of t h e e n c l o s u r e commenced with the stadium wall. vi. Completion of construction.

Architect: Architectural Services Department. Project Location: Salisbury Road, Cheong Wan Road, Kowloon Materials for Enclosure: Paint on grand stand external wall, roofing membrane on precast concrete slabs covering the roof space frame. Completion: 1983

202

The Hong Kong Coliseum

Plate 18.2 View of the Hong Kong Coliseum on top of the KCRC railway station.

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Building Enclosure in Hong Kong

Figure 18.2 Section through the coliseum roof and seating,

roof slab with waterproofing and insulation layers

steel tension rod

space truss roof structure

staircase as entrance to interior

R.C. mega structure

Drawn by ArchiCAD18

204

The Hong Kong Coliseum

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Plate 18.3 Views of the colesium from the podium plaza.

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Plate 19.1 View of Hau Tak Estate with 39-storey residential blocks.

HAU TAK ESTATE Architectural

Firm: Housing

Department

GENERAL Housing for the community is the responsibility of the H o u s i n g D e p a r t m e n t . Here flat sizes can be standardized to cater for different family sizes. Also due to this standardization of plans, elevation design can be standardized to allow production of precast concrete facades. LOCATION Located in Tseung Kwan O new town, this project provides over 7000 flats for 25 000 people. Buildings for residential purposes are designed based on the 'Harmony F blocks which form 39-storey cruciform towers. The site also provides community/amenity facilities and schools for the residents. ENCLOSURE Standardization and modular design allows for building of the precast facades. The advantages of this construction technique are:

1. Finishes can be prepared in the precasting yard for ease of quality control. 2. Steel windows can be cast together with the external wall to minimize water leakage through joints. 3. Overall economics through using standard units. 4. Repeated use of steel moulds for prefabrication saves timber formwork for in situ works. 5. Less in situ works allow ease of programming the site progress. 6. Accuracy of construction can be achieved without in situ tolerances for workmanship. Besides the main elevation as prefabrication, the structural shear walls and floors are cast on site. COMMENTS A particular building type can make use of special construction techniques to improve the construction standards and to decrease possible causes of building defects. The large number of standard units required on a public housing estate makes the technique of prefabrication possible for the enclosure.

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Building Enclosure in Hong Kong

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Plate 19.2 View of Hau Tak Estate with its school and community centre.

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Hau Tak Estate

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Building Enclosure in Hong Kong

Plate 19.3 View of the completed cruciform harmony blocks.

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Hau Tak Estate

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Architect: Housing Department Project Location: Po Ning Road & Sheung Ning Road, Tseung Kwan 0, NT. Materials for Enclosure: Mosaic tiles spray paint on reinforced concrete, steel windows Completion: 1994

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Hau Tak Estate

Figure 19.2 Part section of a Harmony block from the ground floor to the roof level.

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Building Enclosure in Hong Kong

Plate 19.5 Views of part elevation of the completed precast facade.

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Hau Tak Estate

Plate 19.6 Close-up view of the inhabited precast I facade w i t h c l o t h e s d r y i n g and air conditioners installed. J

215

Plate 20.1 View of the Harmony Block under construction.

SHEUNG TAK ESTATE Architectural

Firm: Housing

Department

GENERAL Further to the case study in chapter 19, this project is of similiar nature but focus is on the erection procedure of the enclosure. Again the Harmony Block Concept is used for standardization and thus makes prefabrication possible. LOCATION The site is also in Tseung Kwan O, a residential district with various types of public or private high-rise building blocks.

concrete along the steel window frames using steel moulds. This procedure gives precise construction and ensures no water leakage between the window frame and exterior walls. Mosaic tiles are then built onto the precast elevation unit. This unit is then delivered to the top of the building. Casting is done with the adjoining load bearing wall and floor, minimizing any possible joining problems. The next precast unit will be placed on top and sealed with polysulphide sealant. The floors and shear walls are cast on site by using table and wall formwork which saves time in erection. COMMENTS

ENCLOSURE The standard elevation unit is approximately 2.9 m x 4.7 m staggered 800 mm (approx.) towards the centre to provide variation in the plan and elevation. The elevation unit is cast at the site precasting yard, with

Construction techniques continuously improve and develop to suit increased qualities of living. Good standards of construction avoids future nuisance which might affect the residents. Construction of technique is only a means to improve conditions of life.

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Building Enclosure in Hong Kong

Figure 20.1 Isometric of the precast concrete facade showing a section of the window.

Architect: Housing Department Project Location: Area 59, Tseung Kwan 0 Materials for Enclosure: Mosaic tiles on precast facade, acrylic paint on walls, hot-dip galvanized steel windows Completion: Under construction in 1997, scheduled completion in 1998

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1. in situ R.C. floor slab 2. A/C hood 3. aluminium window 4. precast R.C. wall panel

Sheung Tak Estate

Figure 20.2 Isometric of the precast concrete facade showing a section of the air conditioner support hood.

in situ R.C. floor slab

aluminium window

A/C hood

precast R.C. wall panel

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Building Enclosure in Hong Kong

Plate 20.2 View of the construction site showing tower cranes in operation.

Plate 20.3 Erection of the concrete structure and external wall in progress.

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Plate 20.4 The precast facade is placed on site and joined to the walls by in situ concreting.

Plate 20.5 Steel formwork with working platform is used for construction of the shear wall

Building Enclosure in Hong Kong

Plate 20.6 The construction of the elevation.

222

Sheung Tak Estate

Plate 20.7 View of the shearwall, the elevation, the precast facade in place, the precast facade on site, the precast wall and concrete blocks.

223

Plate 21.1 View of the west elevation from Victoria Harbour.

HONG KONG CONVENTION AND EXHIBITION CENTRE EXTENSION Architectural

Firm: Wong & Ouyang (HK) Ltd. in Association

GENERAL The extension of the Hong Kong Convention and Exhibition Centre (HKCEC) is a complex case. It will house 28 000 m2 of exhibition/convention space and 3000 m2 of meeting rooms. Also included on the top floor is a conference hall with 4500 seats. The complexity of its size and urgency of the project contribute to the sophistication of this case study. LOCATION A 6.5 hectare man-made island at the north sea front of the existing HKCEC is the special site of this development. The prominent nature of the site leads to the importance of the roof form for this medium-rise building. The design takes on a sculptural curve roof form like a flying seabird on the harbour. ENCLOSURE

with Skidmore,

Owings & Merrill,

USA

roof. Several shells are supported by truss systems to build up the 3-dimensional curves. On the top floor, these shells form the roof of the main conference hall with a steel truss spanning 80 m. Two layers of waterproofing membrane give protection to the roof which is finished with aluminium cladding and insulation. The wall enclosure consists of granite, glazing or cladding. Granite is installed using the dry method. Glazing is mainly installed with suspension systems supported by steel trusses. The large area of glazing requires allowance for movement due to settlement and other factors. COMMENTS A variety of building technologies can be combined to make an impressive enclosure. Modern materials can be transformed into innovative components. This project has used sophisticated techniques to build up an architectural image.

The most complex part of the enclosure is the curved

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Building Enclosure in Hong Kong

Plate 21.2 East elevation under construction.

Plate 21.3 West elevation under construction.

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Plate 21.4 Part view of the west elevation under construction.

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Plate 21.6 West elevation under construction.

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Plate 21.7 North tip of the roof and wall in progress.

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Figure 21.2 Part elevation of the north tip soffit and wall.

Architect: Wong & Ouyang (HK) Ltd. in association with Skidmore, Owings & Merrill, USA Project Location: Convention Avenue, Wanchai North, Hong Kong Materials for Enclosure: Aluminium cladded curve roof, glass walls and granite cladding for external wall Completion: 1997

231

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Figure 21.3 Diagram showing wind load to roof:

The architectural roof is a completed system under one specialist contractor including structural metal deck, thermal and acoustical insulation, underlay, waterproofing, membranes, metal cladding, fasteners, sealants, joining and miscellaneous pieces to form a high quality, airtight waterproof and structurally sound enclosure. The metal roof system maintains a minimum of STC-50 over occupied areas.

232

Expansion and contraction joints based on an area not to exceed 10 m 2 or 9 m in any one direction are provided. The roof as the building enclosure is designed to provide a U-factor of 0.35. The roof is also designed to accommodate building maintenance equipment and safety tie-back loading.

Hong Kong Convention and Exhibition Centre Extension

CLADDING

WIND

PRESSURE

NOTES: 1.

2.

3.

LOADS ARE APPLICABLE TO EXTERIOR WALL ELEMENTS ONLY. SEE ORAWING 3 7 0 3 FOR THE BUILDING STRUCTURE DESIGN LOADS. LOADS ARE PERPENDICULAR TO THE PLANE OF THE WALL WITH NEGATIVE VALUES APPLIED OUTWARD (SUCTION) AND POSITIVE VALUES INWARD (PRESSURE). LOADS ARE THE MAXIMUM 'PEAK LOCAL DIFFERENTIAL PRESSURES" AS GIVEN IN THE WIND TUNNEL REPORT.

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Figure 21.4 Cladding pressure on the west and east elevation. The exterior wall is a complete system including all primary and secondary lateral anchors and kickers, stiffeners, fasteners, sealants and joining to form a high quality airtight, waterproof and structurally sound enclosure. The exterior wall system has two distinct but separate lines of protection against water leakage. Both lines of protection are on the exterior side of the insulation. A weep system is provided to drain the cavity created by the two separate lines of protection at each component part of the exterior wall. For granite s u p p o r t i n g systems between support connections to the building framing system, the deflection is limited to L/360 or 13 mm maximum in any direction.

The exterior wall is designed to accommodate building maintenance (window washing) equipment and safety tieback loading supplied by the building maintenance consultant. The building enclosure is designed to provide the following U-factors (watts/deg c/sq. m.): Typical floor vision glass: Winter: 6.0 Summer: 6.0 Ground floor entrances and storefront vision glass: Winter: 6.0 Summer: 6.0 Skylights: Winter: 6.0 Summer: 6.0 Exterior walls or portions of walls other than vision glass: 1.0 Floors over unheated spaces: 1.0

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Figure 21.5 Feature roof axonometric.

MAIN ROOF GEOMETRY

to be fabricated. The deck spanning across the purlins will be flat, parallel edged panels and be perpendicular to them.

General Description The soaring winged form of the main roof appears to be the result of a very complex, compound curve geometry. However, the form is generated by using a simple concept that will be relatively easy to build. The main roof consists of six components: the upper roof which is the vaulted shape oriented to the north (area 'A'), the east and west mid-roof wings (area 'B', 'C'), and the east and west lower roofs wing (area 'D', 'E'), and the south roof (area T'). Generating Geometry The upper roof (area 'A') is a series of segments cut from a tube form. This roof is on the axis of the relative to the ground plan. Since the roof segments are a section of a tube, each segment is buildable with straight, parallel-sided roof deck panels spanning across purlins that are curved to match the curve of the main tube form. The halves of the mid and low roof wings are mirror images of each other. They can be described as vaults generated as multiple curved forms that have a constant profile along their length. These curved forms are tilted and rotated relative to the ground plane, then located in as indicated. The vaults are then clipped using clipping geometries shown or intersections with adjacent roofs and/or curtain walls. A roof form generated in this manner is relatively easy to build. Roof purlins that have the curved profile of the basic roof form are

234

Construction Since the axis of the basic curved form is rotated relative to the building axis, the purlins will be oblique to the orthogonal geometry of the primary trusses and the secondary structural framing. Connectors that can accommodate varying spaces between the purlins and the primary and secondary structural framing below are to be used. Since the basic curved shape is rotated and tilted relative to the building axis and the ground plane, the flow of rain water over the surface will be oblique to the edges of the metal panels that form its finished surface. The joints between the metal roof panels are to be designed to permit large volumes of water to flow over them without leaking. The roof construction will consist of a sandwich of materials as follows. A metal deck will function as the structural diaphragm for the roof. This metal deck will also form the finished ceiling surface for the exhibition and convention halls located below. Sound absorption qualities will be achieved by perforating the metal deck and providing a layer of fibre glass insulation above it. Thermal insulation, a vapour barrier, a furring layer of fire-resistant plywood, a self-healing, fully adhered waterproof membrane or roofing felts depending on the slope of the roof and stainless steel, or aluminium roof with a PVF2 finish complete the sandwich.

Hong Kong Convention and Exhibition Centre Extension

Figure 21.6 Wall type T'. G e n e r a l : Wall t y p e 'F' c o n s i s t s of alternating 1600 mm high bands of azurlite and 900 mm high bands of azurlite, clear glass with a patterned, ceramic frit coating or insulated aluminium panels. The glass is supported at the top and bottom edges by a l u m i n i u m m u l l i o n s . An exterior mullion cap mechanically holds the glass in place. The vertical joints between the glass panes are butt glazed.

1. roof truss 2. 15 mm racking due to differential settlement 3. suspension points for the weight of the wall anchor to the building structure 4. vertical trusses for mullion support 5. anchor points for vertical plates 6. mullions 7. azurlite and clear fritted glass 8. building column 9. anchor points for lateral loads 10 differential movement due to floor imposed load deflections and column shortening: - 15 mm + 15 mm. movement is to be taken at the base of the wall 11 differential movement between columns due to concrete creep and differential settlements +/- 5 mm

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Building Enclosure in Hong Kong

Figure 21.7 Wall type'A'. General: Wall type 'A' consists of 625 mm high horizontal bands of solex (green tinted) glass and insulated aluminium panels. The glass and aluminium panels are supported at their top and bottom edges by horizontal mullions. An exterior mullion cap mechanically holds the glass and panels in place. The vertical joints between the glass panes are butt glazed. The ratio of glass and aluminium bands varies along the length of the wall as the wall decreases in transparency from south to north. The support system: The support structure for this w a l l consists of h o r i z o n t a l aluminium mullions connected to vertical steel trusses spaced at a nominal 2700 mm to 3000 mm centres. The trusses consist of double steel plate vertical chords, cruciform shaped horizontals and are attached to the vertical plates. The steel trusses are designed to resist the lateral loads of the wind and to carry the gravity load of the wall to the roof or floor structure above. The wall receptors and mullions at the base of each wall segment are detailed to a l l o w for v e r t i c a l m o v e m e n t w h i l e restraining horizontal movement.

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1. 15 mm racking due to differential settlement 2. suspension points for the weight of the wall and for lateral loads anchor to the building structure 3. vertical truss for mullion support 4. anchor points for vertical plates 5. building column 6. mullions 7. solex glass and aluminium panels Plate 21.9 Wall type 'A'.

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anchor points for lateral loads differential movement due to floor imposed load deflections and column shortening: - 15 mm + 5 mm movement is to be taken up at the base of the wall 10, differential movement between columns due to concrete creep and differential settlements +/- 5 mm

Hong Kong Convention and Exhibition Centre Extension

Figure 21.8 Wall type 'C\ General: Wall type consists of 1875 mm high bands of clear glass retained and supported at their top and bottom edges by horizontal mullions. An exterior mullion cap mechanically holds the glass in place. The vertical joints between glass panes are butt glazed. The support frame for the wall: it consists of light-weight pipe, plate and rod trusses that span horizontally between building columns (10 to 15 metres). The trusses are spaced vertically at 1875 mm centres (equal to the height of the glass bands). The trusses are designed primarily to resist the lateral loads of the wind. The gravity loads of the glass and the truss supports are transferred vertically via a suspension rod system to the roof structure above. The truss connectors to the building structure and the wall receptors and mullions at the base of each wall segment are detailed to allow for vertical movement while restraining horizontal movement.

suspension points for weight of trusses anchor to the building structural system 15 mm racking due to differential settlement suspension points for weight of glass panes and trusses, anchor to the building structural system building column anchor points for horizontal trusses and system tensioning the weight of the glass panes are

supported by the lower truss, ties to the upper truss serve only to restrain lateral movement 7. horizontal trusses with tension rods 8. differential movement due to floor imposed load deflections and column shortening: - 15 mm movement is to be taken up at the base of the wall 9. differential movement between columns due to concrete creep and differential settlements +/- 5 mm Plate 21.10 Wall type ' C .

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Building Enclosure in Hong Kong

Plate 21.11 Construction of the roof structure — special techniques are required to build the curved roofing system.

238

Hong Kong Convention and Exhibition Centre Extension

Plate 21.12 Structure of the steel truss supporting the central roof.

Building Enclosure in Hong Kong

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Plate 21.13 View of the whole development on the artificial island from Victoria Harbour with Wanchai and Causeway Bay as the backdrop.

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Hong Kong Convention and Exhibition Centre Extension

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Building Enclosure in Hong Kong

Plates 21.14 Fixing various types of external wai

242

Hong Kong Convention and Exhibition Centre Extension

Plates 21.15 Fixing details for the glass panel.

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BIBLIOGRAPHY REFERENCES Brooks, A.J. and C. Grech. 1990. The Building Envelope. Butterworth Architecture.

England:

Building Department. 1995. Code of Practice for Overall Thermal Transfer Value in Building. Hong Kong: Government Printer. HKIA Journal, issue no. 8.9. 1997. Hong Kong: Pale Publication Ltd. Rosen, H.J. and T. Heineman. Architectural Materials for Construction. Wong, W.S. 1991. Building Materials & Technology in Hong Kong. Hong Kong: All Arts Ltd.

FURTHER READING Button, D. and B. Pye. 1994. Glass in Building. England: ButterworthHeinemann Ltd. Goulding, J.R., J.O. Lewis and T.C. Steemers. 1992. Energy Conscious Design. UK: Batsford Ltd. Randall Thomas. 1992. Environmental Design. UK: E & FN Son.