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The Center Light Mass and An eight-pointed star rises vertically on the waterfront in the form of an ultratech office tower overlooking Central and Victoria Harbour. Silvery and reflective by day, the monolith transforms into a light show at twilight when its four angular projections morph into cool neon chevrons. This massive office block offers the largest Grade A floorplates in the SAR and is known — simply and authoritatively — as The Center

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Page 1: Tall Building (ebook) · skyward. At night, the projections are limned in horizontal chevrons of coloured light, completely transforming the building’s presence while retaining

The Center

LightMass

and

An eight-pointed star rises vertically on the

waterfront in the form of an ultratech office tower

overlooking Central and Victoria Harbour. Silvery

and reflective by day, the monolith transforms into

a light show at twilight when its four angular

projections morph into cool neon chevrons. This

massive office block offers the largest Grade A

floorplates in the SAR and is known — simply and

authoritatively — as The Center

Page 2: Tall Building (ebook) · skyward. At night, the projections are limned in horizontal chevrons of coloured light, completely transforming the building’s presence while retaining

When architect Dennis Lau(Chairman & Managing

Director of his eponymous firm) talksabout The Center, the enthusiasmhe feels for the building in specificand Hong Kong architecture ingeneral becomes palpable. Heeagerly sketches responses toquestions by tearing off sheets froma roll of tracing paper, literallyretracing the design process. Ash e d e s c r i b e s h i s m o d e r nreinterpretations of traditionalChinese gardens, his fingers fly tothe bookshelf, plucking a volume ofSuzhou stone masterpieces toillustrate his words. Lau’s fondnessfor the SAR, mastery of his craft andpassion for the new 80-storey officetower are much in evidence. Whenasked about possible alternatedesigns for The Center, he points tothree scale models enshrined inglass cases — all fascinating andworkable designs that ended up onthe “cutting room floor”. The finaldesign reflects Lau’s passion for hiscraft, developer Cheung Kong’sdesire for a landmark office tower,and the considerable vagaries of thesite itself.

Hong Kong’s historical sliceThe Center is located in one of HK’solder districts — midway betweenCentral and Sheung Wan. The siteoffers prime vistas of Asia’s mostscenic cityscape and harbourfront,

Page 3: Tall Building (ebook) · skyward. At night, the projections are limned in horizontal chevrons of coloured light, completely transforming the building’s presence while retaining

but was also home to a rabbit warrenof “lane communities” — shopsarranged along narrow parallellanes. Twelve years ago, the LandD e v e l o p m e n t C o r p o r a t i o nearmarked the problematic site forredevelopment, but the wheels ofprogress ground on for nine yearsuntil construction finally began.Acquiring the land from a myriad oflandlords was one problem. Otherproblems were posed by thegrowing pains of urban renewal —previous redevelopment in the areahad been undertaken piecemeal,rendering a wholesale razing of thearea unfeasible.

Denied a completely clear site,Lau designed the signature eight-pointed star plan of The Center tosuit the irregular environs. This

geometric plan can be described as“squa re -upon -squa re ” . Thediamond-shaped projections alsomaximise views from every angle.

Lau was interested in maintainingthe “lane community” concept,perhaps under glass canopies. TheLDC (whose logo, interestinglyenough, was designed by Lau yearsago) was more in favour of creatingcirculation space for community use.

Gazing upwardLau ’s c rea t ion ach ieves animpression of tremendous mass,which is potentiated by the urbansqueeze of its surroundings. HongKong is not known for its shy andretiring office blocks, but evenc o m p a r e d t o o t h e r s h i n yheavyweights, The Center is

Page 4: Tall Building (ebook) · skyward. At night, the projections are limned in horizontal chevrons of coloured light, completely transforming the building’s presence while retaining

battleship-massive. In daylight, thebase of the building provides themost impressive view, as thei n v e r t e d - p y r a m i d s o f t h eprojections merge into the silverybui ld ing s ides and cont inueskyward. At night, the projectionsare limned in horizontal chevronsof coloured l ight, completelyt rans fo rm ing the bu i l d ing ’spresence while retaining its profile(see sidebar: “Light Show”). Theoverall impression is that of astructure which is already part ofthe next millennium — a futuristicoffice block whose appearance isin lockstep with its host of high-tech facilities.

Counterbalancing this impressionof mass is the use of light within a

confined urban space. The buildingmaterials for The Center werechosen to admit or reflect light.Surfaces on the lower floors —including the twelve main columnswhich support the building frame —are largely done in embossed-pattern mirror-finish stainless steelcladding. This shiny stippled steelplate is an emphatic flourish whichlends an air of polished industry.Mirror finishes are in abundance; thestructure bristles with chrome rivetsand metal detailing. Glazing is usedextensively.

T h e b u i l d i n g ’ s c o l o s s a lentrances are a Dennis Lau & NgChun Man trademark. The lobby ison a similar scale; at ground level,i t s e e m s t o s w a l l o w i t s

surroundings in every direction,including straight up. Lau pointsout that while the lobby appearsmassive, it is in proportion to theremainder of the building. A quickglance at the section drawingconfirms his point.

Gaining entryThe building presents identicalfacades on all four sides, yet theentrances vary considerablydepending on the approach. DesVoeux Road Centra l has anentrance with a pair of escalators forthose arriving by tram, and theJubilee Street side — oppositeCentral Market — houses the mainvehicular entrance. A side entranceon Gilman’s Bazaar is approached

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via a gigantic staircase finished inthat distinctive chrome stipple.

The main entrance and publicdrop-off is on Queen’s Road Central,where the building is approachedacross a 1,500 sq m open plaza.This space is open to the public 24hours daily, and incorporates a“bamboo garden” which Laudesigned as a modern answer to thestone wonders of Suzhou. Glassfacades flank the plaza, which iscomplemented by a water featureand a “tree pit” stocked withf lour ishing green bamboo. Apedestrian corridor is defined by anoverhead awning supported by asingle row of columns; this fullyglazed canopy provides protectionduring inclement weather.

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The pair of glazed doors frontingthe corridor can be difficult to notice,as one is distracted by the expansivesteel and glass of the building’s core.Persevering through those doors,the 12.4-metre main lobby revealsitself as a transparent box. Glazedpanels are supported by chromedtension cables in a vertical tensilearrangement; support is supplied bythe steel frame and structural slab.To the right is a pair of escalatorsleading down to future GI/C(Government Inst i tu t ion andCommunity offices), the executivedrop-off area and the singleexecutive lift, which offers secured-card access to any floor in thebuilding.

Straight ahead, a bank of threeescalators leads upward to the

transition lobby. The escalators areflanked by “bubble tanks” — rowsof cylinders filled with water andbubbling away. A waterfall wassuggested, but it was felt thatallowing the water to drain awayfrom the building constituted badfeng shui; the bubble tanks allowthe direction of flow to continueupwards into the building. A seriesof misting devices at the base ofthe bubble tanks creates a low-intensity, soothing fountain effect.

The transition lobby is a spaciousplane finished in unique grey-greenBrazilian granite (unique as thesingle quarry which produced it hasnow closed down). The lightness ofthe stone colour is singular. It is herein the transition lobby where thetransformation from the straight lines

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and triangulation found in thecolumn arrangements starts to shiftinto the circular theme whichd o m i n a t e s t h e b u i l d i n g ’ sinterior. A large design element ofconcentric circles appears on thefloor of the transition lobby and isechoed by a round skylight directlyabove.

Directly in front of the escalatorsis the spacious glazed entrance tothe anchor tenant’s retail shop. It ishere that the slow curve of the retailarea begins. Although retail is notThe Center’s raison d’être, a seriesof shops is available for everydaytenants’ needs. Even without aburning desire to go shopping, astroll along the semicircular glazedwalkway provides wonderful viewsof the building core, columns andelevation. The curving arcade alsoscreens views of the older concretebuildings which surround TheCenter, and the semicircular spaceis topped by a landscaped gardenwhich provides further screeninggreenery.

To the right of the anchor tenantshop and the arcade walkway isanother triple bank of escalatorswhich leads to the raised lobby,where the vertical transport schemebegins to take shape. As with anytrue skyscraper, lift logistics arecritical — The Center utilises a“shuttle lift lobby” at the raised lobbywhich helps to manage traffic by

Page 8: Tall Building (ebook) · skyward. At night, the projections are limned in horizontal chevrons of coloured light, completely transforming the building’s presence while retaining

shuttling passengers betweenseven lift zones. People bound forzones 1, 2 and 3 can board lifts atthe raised lobby. So too can thosebound for zone 7, the exclusiveupper zone which is direct lyaccessed from this lobby.

Those headed for zones 4, 5and 6 start at the center of theraised lobby, where another floor-design motif of translucent greenconcentric circles houses watersprays and coloured lights. Thisdramatic underfloor fountain isknown as the “starburst waterfeature”. It marks the starting pointf o r t h e l i f t s w h i c h w h i s kpassengers to the skylobby on the42nd floor.

Taking the “Express”Few buildings in the world are loftyenough to require skylobbies, yetthey are an essential tool in verticaltransport management for tallbuildings. The idea is simple:passengers collectively take an“express” lift to a central location,then separate into “local” l iftsserving different floors which takethem to their final destination. Theconcept is similar to commutersusing a combination of expressand local trains to reach theirindividual stops.

Use of a skylobby effectivelycreates a second “main lobby” areawithin The Center, albeit one with

rather more spectacular views. Thearchitects have taken full advantageof the skylobby by siting a five-starfood and beverage outlet at thisjunction. A restaurant with fullglazing wraps itself around half ofThe Center, bookended by a pair oflounges for those simply enjoying adrink or a fine Havana — the facilityhas an impressive cigar menu tocomplement the i r beverageselection. There are a pair of officeunits available on this floor as well.The Center’s office zenith is thepenthouse on the 80th floor, whichpresents a stunning 360-degreeview akin to that from a low-flyinghelicopter.

Acres of silverThe silver metallic sheen of thecurtain wall defines the building indaylight hours, and stands in sharpcontrast to its luminescent nighttimeprofile. As might be expected, thechoice of curtain wall was not anarbitrary one — with no sunshadingto speak of and a huge surface area,The Center relies on its envelope tocut solar gain and keep a damperon tenants’ energy bills. Typical unitsare Varicon 17.5 mm silver-on-clear,a configuration which limits solartransmittance to a mere 8%.Spandrel units have a 10 mmthickness and a horizontally stripedpattern. Mullions are finished innatural anodised aluminium.

Page 9: Tall Building (ebook) · skyward. At night, the projections are limned in horizontal chevrons of coloured light, completely transforming the building’s presence while retaining

Befitting its high-tech image, TheCenter employs a curtain wallcleaning system which is fullyautomated. The cleaning gondolasdescend from the top of the buildingon tracks concealed within themullions. Cleaning can be carriedout at night to minimise disturbanceto the building occupants.

Technological ImplementationGrade A office space necessitatesdesign which reflects currenttechnology and allows tenants toimplement their own technology. Asour working lives become more

complicated, the function of officetechnology should be to make ourexis tence s impler and morerewarding.

Raised flooring is now a standardfeature in new office buildings;Companies are loathe to move intooffices which offer no flexibility fortheir IT cabling requirements. Inaddition to its raised flooring, thestructural cabling system (SCS) forThe Center plays a critical role in allte lecommunicat ion systems,providing the physical link betweensources and dest inat ions ofinformation. Data, voice, video and

At 346 metres to the top of the mast, TheCenter is the third-tallest building in HongKong. Central Plaza, also designed byDennis Lau & Ng Chun Man, is 374metres tall by the same measurementstandard. IM Pei’s Bank of China Buildingtops out at 368.5 metres.

59 floors of offices are available, with atotal GFA of 130,032 sq m of office space.

The Center is the largest-scale steel-framed office in Hong Kong. A total oftwelve steel box section columns supportthe building — the columns are concrete-filled for 20 storeys, then reduce in sizeand become hollow as they reach the top.

At 2,415 sq m, the floorplates in TheCenter are the largest amongst all officebuildings in Central.

A total of 35 high-speed passenger liftsand 6 service lifts form the verticaltransport network for The Center.

Over 400 carparking spaces are availablein the basement carpark.

FAST FACTS

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control signals are transmitted overthis infrastructure, which linksdevices throughout the building.

The SCS consists of Category 3/Category 5 (UTP) copper cables andoptical fibre cables, and is capableof supporting high-speed/broadbandservices such as ISDN lines forvoice, 100 Base-T Ethernet for data,and video signals, and is designedt o a c c o m m o d a t e f u t u r etechnologies. Tenants can easilymake multi-floor connections, andit’s even possible for tenants toconnect on alternate floors. CheungKong’s Senior Project ManagerGrace Shen detai ls the mainadvantage of designing the buildingfor IT use: “With The Center, youdon’t need to spend much moneyfor interior fit-out.”

Flexible AirThe 340 mm underfloor void of TheCenter is unique in that it houses anair -condi t ioning system wi th

relocatable air diffusers built into thefloor. This is the first air plenumsystem in Hong Kong — the voidunderneath the floor is filled withcold air which is piped into theworking space via individualunderfloor units. This design allowsfor maximum flexibility as the air-conunits (the units interchange with floortiles and are thus known as “fan-tiles”) can be installed or removedas needed. This eliminates the needfor ductwork and allows officepartitions to be reconfigured easily.The system permits end-users toadjust temperature and volume of aircirculation to suit personal tastes, orto compensate for heat-generatingequipment.

Air circulation in each office isfurther improved by a ceiling-mounted recirculating air systemand air-filtering system which routes

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Cheung Kong (Holdings) Ltd/

Land Development Corporation

developer

Dennis Lau & Ng Chun Man

architect

Maunsell Consultants Asia Ltd

structural engineer

Associated Consulting Engineers Ltd

m&e

Davis Langdon & Seah (Hong Kong) Ltd

quantity surveyors

Ryoden

HVAC

Paul Y - ITC Construction Ltd

main contractor

Tostem

curtain wall

Chevalier

lifts & escalators

Arbitare/BSC

signage

t h e a i r r e t u r n t h r o u g h t h einterchangeable light reflector unitsin the ceiling. Shen: “It’s all aboutuser control and keeping the airc lean. The underf loor spaceprovides ease of maintenance as itis simple to vacuum.”

The building also bristles withtechnological frills at the public level.LCD screens in the passenger liftsdisplay weather data and can beprogrammed with the company logofor firms leasing an entire floor.Touch-screen directories are locatedin the office lobby, while lobbyscreens display financial data,weather and news headlines. Thetrump card is the huge SonyJumbotron display screen on theQueen’s Road Central side, whichpresents newsfeed information andcan also be used for special events.

Filling the ColossusThe abundance of office space inthe SAR has made the sector atenants’ market. Buildings whichre f lec t qua l i t y and pres t igecombined wi th an exce l len tlocation will be more successful atattracting tenants. The location ofThe Center — close to the Mid-Levels escalator, the Hong KongAirport Express stat ion, andmyriad MTR/tram/bus/road links —is prime. But Shen also points tothe building’s facil it ies, whichinclude such amenities as showers

in the executive washrooms, as amajor selling point. The proof of thepudding is the tenants who havealready taken space, includingD a o H e n g B a n k , S a m s u n gElectronics HK Ltd, Celestial AsiaSecurities Holdings Ltd and theLDC. Others wishing to becomecentrists are advised to view theshow flat on the 43rd floor.

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The night-lighting features of TheCenter are so dramatic that they

have become a symbol of thebuilding itself. They have been therecipient of praise and scorn, butmore than anything else, they haveplaced an indelible stamp on HongKong’s famed nighttime skyline. Insharp contrast to the normal practiceof training spotlights on a buildingto articulate its curtain wall, fins andornamentation in the night hours,The Center’s neon scheme leavesthe walls of the building dark as benthorizontal str ipes cl imbs thepyramidal project ions of thee leva t ion , cu lm ina t ing in atrapezoidal flurry of lumens at thebuilding’s crown.

The lighting scheme was suppliedby Far Display Lighting Ltd, asubsidiary of Hong Kong-based FarEast Neon Light Co Ltd. The systemis a COZY® VIVID low-voltage neonsystem which uses primary-colourneon tubes to achieve a wide varietyof effects. The 8,784 tubes areevenly divided between red, blueand green; combinations of thesecolours will create any desiredcolour. The total power consumptionis approximately 110,000 watts,although a conventional high-voltage neon system of identical sizewould consume four times as muchelectricity. About 11 kilometres ofneon tubing was used.

The system has a total of 14preset settings, three of which aresolid-colour and can be used for

checking the entire lighting system.The everyday presets involve slowand subtle changes, which alwaysm o v e f r o m b o t t o m t o t o p ,accelerating the upward thrust.There are presets for holidays — theChristmas effect will evoke a greenand yellow Christmas tree with multi-coloured sparkles, and the LunarNew Year setting will alternate red/gold/yellow/green with bloomingrainbow colours. The most dynamiclighting effect is where the buildingimitates a fireworks display going off,with rapid colour rushes toward thetop followed by slower particles ofsparkling colour falling downwards— an effect that will manifest duringpyrotechnic displays in the harbour.Currently, the system presents asingle “fireworks” cycle at 9:00 PMand a single “holidays” cycle at10:00 PM.

Working in unison with theneon lighting is a series of Italianspot l igh ts known as “spacecannons”. This particular chargeof the light brigade takes placemostly at the top of the building,where space cannons in 4,000-,2 , 0 0 0 - a n d 1 , 0 0 0 - w a t tconfiguration light up the rooftopmast with its double-paraboladecoration. An additional quartetof space cannons will train 4,000watts of firepower on the lowerport ion of the bui lding. Al l ofthese ultra-tech spotlights arewired into the main system andwill change colour as required.

Light Show

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The CenterConstruction of

April 1995 ,when the contractor wasdoing the foundation work. On the lefthand side of the photo is Jubilee Streetand on top is Queens Road Central. Inthe middle, several machines aredigging the vertical trench for theconstruction of the diaphragm wall

A ser ies of 1.2-metre thickdiaphragm wall panels were joinedto form a 24-metre diametercaisson shaft. Four of thesecaissons were built to provide asound base for the foundation ofthe main structure of the buildingtower. The photo shows theexcavation work using typicalexcavating machines inside one ofthe caisson shafts

Overall view of the automaticcirculation trench cutter

by Raymond Wong Wai Man

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Close up showing the twindrum cutter set. A 150-millimetre suction pipe isplaced between the drumcutters. The excavated soilor gravel isbeing sucked outfrom the trench togetherwith the bentonite slurry.The slurry is then pumpedto the bentonite treatmentplant where the soil andgravel are removed by afiltration process

An overall view of the four caisson shafts which form the major part offoundation system of the building. A typical work stage can be seen here,starting from the excavation, construction of the bottom raft, erection ofthe structural steel column clusters and the onward fabrication of the columnstructure respectively

Detailed close-up of atypical caisson shaft. At thisstage, the structural steelc o l u m n c l u s t e r h a sessentially been completedup to the ground level. Thescaffold inside the shaft waserected as further supportfor the construction of thepodium structure of thebuilding

The main frame of the building tower risingfrom the ground. The four column clusters thatsupport the building, each composed of three2.5m x 2.5m and one 1.2m x 0.8m steelcolumns, can be clearly seen here. Onespecial feature in the structural design of thisbuilding is that it does not consist of areinforced concrete central core, which is quiteunusual in buildings of similar type. The wholebuilding is based on the design concept of agigantic space frame in order to achieve thenecessary rigidity in structure

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The overall layout of the site on June1996. At this stage, the basicstructure of the podium had beenformed. Since most of the basementstructure was constructed using atop-down technique, there was noactivity until a later stage, when thepodium structure was completedand access to the ground was madeava i lab le fo r the basementexcavation

A work platform attachedto a corner column toprov ide access fo rworkers to carry out thenecessary welding work

A 5-metre reinforced concrete raft wasconstructed in the bottom of thecaisson to form the foundation for thecolumn clusters of the building tower

At this level — some 180 metresabove the ground — a workerprepares a lifting rope for the placingof a connecting member

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The core frame at the centre ofthe building. This core measuresroughly 25m x 25m, and willaccommodate a pair of stairsand the requi red escapepassageways, lavatories, airhandling unit rooms and 26passenger lifts

The composite floor, which acts as a diaphragmstructure which provides rigidity to the verticalsteel members, is constructed of reinforcedconcrete laid on a ribbed steel deck as apermanent shutter. The one shown here is thedeck prior to placementof the floor reinforcement

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A complicated con-nection arrangement at the junction of theinner columns and the floor joists

A detailed look at one of the four corner gusset blocks whichconnect and provide the required rigidity for the pyramid structureand the mast

The dimension of the main frame is reduced and set backto form the “pyramid” top of the tower. The details of thestructural arrangement for the housing of the 80-metre mastcan also be seen

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The temporary tack rail system provided at 30-storey intervals for the manoeuvring of thegondola used for the erection of the curtainwall panels

The curtain wall system used in The Center has a simpledesign due to a unitised system combined with therelatively simple and plain form of the building exterior.The only exception is the “half-pyramid” located at thetop and bottom of the four cantilevered attachedportions. The one here is the inverted half-pyramid —with the bracket for the suspending scaffold partiallyerected in preparation for the erection of the backingframe and curtain wall at a later stage

Close-up of the partially completed steel mast.Due to the height of the free-standing mast,a resonant wind effect which creates lowfrequency vibration must be considered. Aspecial resilient design is used to stop thevibration from transferring to the mainstructure below

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May 1997

January 1997

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One of the prominent designsemployed in The Center is theautomatic curtain wall cleaningsystem which occupies almost theentire area of the 80th floor. Witha retractable gate door on eachside of the facade to launch thegondola, the cleaning system cancover all the wall surfaces of thebuilding exterior. The photo showsthe gate door opened with the rail-mounted crane-car equipped witha telescopic arm launching thewindow cleaning gondola during atrial operation

The operation of the curtain wallcleaning gondola and the crane-caras seen from a distance

Workers inside the gondola carry outa commissioning test before thehandover of the system. A controlpanel inside the gondola can steer thegondola to any position on the exteriorsurface of the building

Stage 1 Stage 4Stage 3Stage 2