8/22/2019 Has_Housing Typology in HK

1/1

HOUSING TYPOLOGYIN HONG KONGWHAT DRIVES THE TRANSFORMATION?

ROW HOUSE MASSIVE BLOCK PODIUM AND TOWER

EMERGENCY HOUSING SLAB HOUSING TRIDENT / HARMONY

Public housingin HongKongis a set ofmass housingprogrammes through which theGovernment ofHongKong provides aordablehousingfor lower-income

residents.It is a major component ofhousingin Hong Kong,with nearly halfofthe population now residingin someform ofpublic housing.[1] Thepublic housing

policy dates to 1953,when a rein Shek KipMei destroyed thousands ofshanty homes and prompted thegovernment to begin constructinghomes for the

poor.Public housingis mainly built by theHongKongHousing Authority and theHongKongHousingSociety.Rents and prices aresignicantly lower than those

for privatehousingand are heavily subsidised by thegovernment,with revenues partially recovered from sources such as rents and charges collected from car

parks and shops within or near theresidences.

Row housewas a widespread buildingform in theSouth Asia area,such as HongKong,Singapore,Taiwan and Malaysia.Although variations ofthis form can befoundin dierent area,thegeneral characteristics is that is has a narrow frontageand deep lot. Theground oor is often used for commercial purposes and theoors aboveareused for living.It was theearliest urban built typology in HongKong by thetimethe British rst arrived in HongKong.However,with therapid growth ofpopula-tion,this built typology in Hong Kongquickly transformed in order to accommodatemorepopulation whileaddressing thehealth and safety concerns.

Therst stage ofpublic housing emerged after thedevasting rein 1953. Therefore,thehousingwas very simpleand responded to thebasic needs ofliving. Each unit hasno amenities.Bathrooms werelocated outside the living units and shared amonghouseholds on thesame oor.There weresix storeys per buildingand 60 rooms peroor.Each unitwas 11.15sq.m in size and accommodated veadults,makingan occu-pancy ratio of2.23sq m per person.Cookingfor thefamily was on theaccess corridoroutsidethefront door.

Theslab housingrepresents the second stageof public housing.In additi on to proving aplaceto stay,public housingwas moving towards better livingenvironments.Each unit wasdesigned with bathroom and cooking area.Also, each unit had morewindows opened tooutside.This helped for improvinglightingand ventilation oflivingenvironment.In addition,each housingestate had better support facilities within theneighborhood,such as school,shoppingarea,day care and elderly support.

Trident and Harmony reprTrident and Harmony represents thethird stage ofpublic housing.Thespace standards and livingenvironments havefur-ther improved.Theoccupancy ratio has increased from of2.23sq. m per person in 1950to 4.25sq meper person in 1980s.Each unit had equippedwith livingroom,kitchen, bathroom and one,-two-three-bedroom.Bedroom,living room,kitchen and bathroom had individual window openingtoexterior.This was to ensure natural daylight and ventilation could reach theeach space.Also, new social needs called for facilities for elderly andsinglepeopleto be integrated with theoverall plan.In addition,there was a greater attention paid to designingpassiveand active recreation areawithin open spaces between thetower blocks.Theseareas also functioned as impor tant community areas for theresidents outside oftheir high-rise,high density indoor units and corridors.

Massiveblock was a new buildingtypology emerged after a changeof buildingregulations,which allow a far greater oor area and buildingmass to bebuilt on a given site.A new BuildingOrdinancewas madein 1956to allow private developers to providemoreaccommodations fora given sitein order to reducethepressureof housingneed stimulated by theinux ofnew im-migrants from mainland China.With thenew Ordinance,the limit ofbuilding height was dou-bled from previously 70-80ft (21.3-24.4m) and plot ratios ofbetween 18:1and 20:1 werepossi-ble.Buildings less than ninestoreys werenot required to providelifts.

Although massiveblocks providesubstantial increaseofnew housing,it also increased thedensities ofcities and placed excessivepressureon theneed ofinfrastructure (e.g.water,sewerage, powerand rubbish collection) and neighborhood facilities (e.g.schools,day-care and public facilities).Also,themassive blocks werebuilt very closeto each other and therewere enough lightingand ventila-tion for streets and rooms.Therefore,thegovernment decided to review thebuildingordinance.A new BuildingOrdinance was then released in 1966to reducetheplots ratio to around 8:1.The regula-tion also was designed to reducethesite coverageof building.New buildingcan either havehigher plot ratio with lower sitecoverageor lower plot ratio with higher sitecoverage.There was a slidingrelationshipbetween plot ratio,buildingheight and site coverage.As a result,private developers can either build reasonably massiveor tower on podium,but not both.

10

20

30

40

50

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

10

20

30

40

50

1930 1940 1950 1960 1970 1980 1990 2000 2010

THE SEARCH FOR DENSITY

PRIVATE HOUSING

1953

1970s

DEVASTINGFIREOn Christmas Day of 1953 over

50,000 squatters were left homelesswhen a fire sweptthrough the ShekKei Mei settlement in HongKong.Within 53 days of the tragic fire, thesite was cleared, and the firstrows oftwo storey emergency housingwere

completedby public housing

1960s

LANDwas stillin very shortsupply andtens of thou-sands of people were stilleither homeless or lvinginre-establishedsquatterareas. The 1960s sawtheintroduction of lifts, centralcorrtidor access andtheprovision of abalcony witha toiletanda fresh watersupply pointfor each unit

1980s

LANDwas stillin veryshortsupply andtens ofthousands of people werestilleither homeless orlvingin re-establishedsquatter areas. The 1960ssawthe introduction oflifts, centralcorrtidoraccess andthe provision ofa balcony with a toiletanda fresh water supply pointfor each unit

1990s

LANDwas stillin veryshortsupply andtens ofthousands of people werestilleither homeless orlvingin re-establishedsquatter areas. The 1960ssawthe introduction oflifts, centralcorrtidoraccess andthe provision ofa balcony with a toiletanda fresh water supply pointfor each unit

SOCIAL ENVIRONMENT

DEVASTINGFIREThe fire in Shek Kip Mei, HongKong on Christmas day of 1953 left53,000 peoplehomeless. This resulted in an urgentneed for emergency housing. The HongKonggovernmentrespondedvery quickly. The site was cleared, andthe first rows oftwo-storey emergency housingwere completedwithin 53 days. The building program con-tinueduntil there were enough units to house 36,000 people.

Fire continuedthrough the next 12 months and, by December 1954, nearly 100, 000people, around1 in 20 of the urban population, hadbeen made homeless. The HongKonggovernmentcontinued the buildmore emergency housing. By December 1954,eightH-shapedblocks, six-storey high, toweredover the two storey emergency hous-ingwere built. In the followingyear, the emergency housingblocks were demolishedandwere replaced by 21 seven-storey blocks.

No.89-93Highstreet

FAR: 3.0

DU/AC: 272

POP/AC: 1091

LEE TUNG STREET

FAR: 5.6

DU/AC: 333

POP/AC: 1335

KOWLOON WALLEDCITY

FAR: 12

DU/AC: 1110

POP/AC: 4313

MAN WAI BUILDING

FAR: 10.1

DU/AC: 598

POP/AC: 2394

69HIGH STREET

FAR: 15.4

DU/AC: 633

POP/AC: 2533

THE GRANDIOSE

FAR: 15.2

DU/AC: 502

POP/AC: 2009

BUILDING HEIGHT

MING WAH DAI HA

FAR: 4.1

DU/AC: 339

POP/AC: 1356

FUNG WO HOUSE

FAR: 4.6

DU/AC: 314

OP/AC: 943

KWONG MING COURT

FAR: 12.5

DU/AC: 610

POP/AC: 2440

ALDRICH GARDEN

FAR: 5.8

DU/AC: 330

POP/AC: 1321

THESEARCHFORLIGHTANDAIR

1903PublicHealth Ordinancewas enactedin 1903 which specifiedthe provisions ofopen space atthe rear ofthe building, ensuringventi-lation to rooms atthe back. Italso reducedthe per-missible buildingheight, which was limitedto thewidth of the street, down from one anda half timesthe width of the street. The implications ofthe newregulations reducedconsiderably the habitable spaceon a particular site. Since there was no reduction inpopulation, the demandfor habitable space didnotdecrease. Therefore, illegal extensions began toappear on the roofs of buildings, andpeople use thestreets andback alleys for cookingandwashing.

1935First BuildingOrdinancePublic Health Ordinance wassplitinto BuildingOrdinance andPublic Health Ordinance. Thepermissible depth of a buildingwas further reducedto 10.7m.The heightof row houses werelimitedto three to four storey,includinga ground floor shopwith 13.3m deep;4.1m wideand4 meters between floors;afrontcolonnade; and a smallback kitchen nextto a coveredyard. With this newregulation,standardbuilding heights werelimited to three storeys unlessbuiltof fire-resistantmaterials.

In the 1890s, bubonic plague was spreadingthroughoutsouthern China, as notedabove, and by 1894 haderuptedin Guangzhou (Canton), GuangdongProvince, 87 miles upthe Pearl River Estuary from HongKong. (10)Thus beganthe 30-year HongKong bubonic plague epidemic, which ended in 1923 after afflicting21,867 people of whom20,489 died, an astonishingmortality rate of93.7%. (10,11) The peak of the epidemic was in the firstyear, 1894:2,679 cases and2,552 deaths. In the second year, 1895, only 44 cases were reported. Thereafter the number of

cases fluctuated from year to year between 2 and 4 digits, upto the year 1923. During the outbreak of plague,many volunteers helpedoutto search for plague cases and disinfecthouses. Because of the diseases, goodventila-tion andenough sunlightbecame importantconcern for building regulation.

After the surrender ofJapanese in 1945, many former Chi-nese residents returnedto Hong Kong. From 1951 to 1966,there was an increase ofhalf-an-million inhabitants for eachfive year. Mostpeople were living in cubicles. Given theenormous needof newhousing, the HongKonggovernment

introducedpublic housingprograms andnew buildingcodesto encourage allowfor far greater floor area andbuildingmass on any given site.

MassiveBlocks

Since massive blocks were builtvery close to each other and there were enough lightingandventilation for streets androoms, a newregulation in1966 was released. The newregulation triedto balance the needofmaximizingthe retailfrontage on the ground floorandimproving the lightingandventilation ofhousingabove. Under the newregulation,the ground floor can have 100%coverage for non-residentialuses, which forms thepodium. The residentialtower above the podium has to fulfillthe slidingrelationship ofplotratio andbuilding heights. Podium has then later extends to severalstories andpro-vides parking, recreation andsocial spaces. Italso reduces the noise from the streets.As a result, podium and tower becomes a popular housingtypology in HongKong.

Towers

The minimum distance between building blocks was basedon theconceptof verticalangle requirementof 71.5 for livingroom andbedrooms anda minimum glazingto floor ration of10%. As a result,under the regulatory framework, developers can build towers veryclose to each other. This results in insufficientlight andair for the

groundleveland the units inside. The photo on the rightwas takenfrom the groundfloor of lightwell formedby a groupof residentialtowers looking up towards the sky in Hong Kong (by ProfessorEdwardNg, from the Chinese University of Hong Kong).

Lightwell within tower blocks

1956BIRTHOF MASSIVEBLOCKSBuilding Regulations allow the heightandmass of city buildings to expand enormouslybecause the newbuilding materials (particularreinforced concrete for flooring rather thantimber)were safer. Also, lifts were becomingmore affordable in high rise construction.Under the new regulation, building heighttwice the streetwidth in height was allowed.The limitof buildingheight was doubledfrompreviously 70-80 ft (21.3-24.4m) and plotrations ofbetween 18:1 and20:1 were possi-ble. Buildings less than nine storeys were notrequired to provide lifts. There were somerequirements for the upper floors to setbackfrom the streets andthe provisions of lightwellin order to ensure the lightingand venti-lation conditions ofstreets andunits.

1966BIRTHOF TOWERAND PODIUMWith the newregulations in 1966, plotratios fell substantially from 18:1 to8:1. Other than plot ratio, the newregulations also introducedmore vari-able to ensure enough light and airinto the units. Itestablisheda slidingrelationshipbetween plotratio, build-inghe ight andground cove r:w i t hincreasedheightand plotratio, butreducedsite cover. Heightcontinuedtobe relatedto streetwidth, andbuildingenvelopwas relatedto an angledcal-culation from the streets centre line.Under the newregulations, one couldbuild reasonably massively or standtalland slim on a site butnot both.

2005FURTHERCONTROL OFDISTANCE BETWEEN BUILDINGBLOCKSThe practice note PNAP278 is introduced in 2005 to further regulate theamountof lightand air in high density residentialbuildingblocks.Insteadof usingthe previous conceptof verticalangle requirementof71.5 for livingroom andbedrooms anda minimum glazingto floorration of 10%, the newpractice note introduceda conceptcalledUnob-structedVision Area (UVA)requirement. Architects can use the formulato calculate the requiredUVA through interchange the heightof building,windowsize or open space in frontof building block.

BUILDING ORDINANCE IN HONG KONG

ABuildingBuilt to BuildingOrdinance1903 ADiagramin the1956 BuildingRegulation ADiagramin the1966 BuildingRegulation

PlagueReachesHongKongin 1894

notes:The Ordinance of 1903 restrictedthe heightof buildings shouldnotexceedthe width of street. It also constrains the open space outsidewindow, size of glazingandwindowopening, heightof storey anddepthof room from the window. The goalwas to controlbuildingdesign forbetter lightandair. There were also sufficientgaps andopen spaces-ofa certain proportion-between buildings so that interior spaces couldbeeffectively lit, cross-ventilatedandaccessed.

< volunteers search plague cases anddisinfec thouses

a

area b= WxW1 Max W

Max H= 2W

Max H= 2W

Small block podium + tower typologies:

Theseappeared on amalgamated lots (2-4) within established street blocks.Squeezed between existingstreet-a ligned building, thetowerscould riseas a stepped aligned buildings,the towers could riseas a stepped-back element between neighboringbuilding (left) or to one

sideofthe building(middle) or as a freestandingelement towards thepodium centre(right).

frontwindow> A/10 rear window=10 sq. ft

footbridge 36 allowed

Area B

street max 40

Area A

BldgHT< streetwidth

(1/2 of its openable)

(max =75)

W1

W

Area a equals 2W1xF1

F1

F

Area C> (A+B)/2

6 scavenginglane

typicalwidth 15

A= KH2

Ais theUVAin f ront of thewindow

H is theheigh t of thebuilding containing thewindow to betested

K is a coecient and needs to bedevised using parametric tests

H

A

H