Cover Story: Building A Smart City (Part 2)
July 03, 2017
PUBLIC HOUSING DESIGN IN EVOLUTION
There was no Housing Authority (HA) in Hong Kong until 1973; its history can be traced back from the rehousing of fire victims in the first resettlement estate in Shek Kip Mei in 1954, marking the birth of Hong Kong's public housing programme. In connection with a background of vigorous economy and growing aspirations for better living conditions, the public housing estate transformation process is a vivid reflection of the economic and social changes of Hong Kong (HK) in the past five decades. Let's take a look at the interesting designs of public housing buildings from different eras, says Housing Department architect Jo Ngai.
1954 The Past
"H"-shape;"I"-shape
Eight six-storey resettlement blocks were built mainly in a "H" shape, in the styles known as Mark I and Mark II to rehousing of 50,000 homeless families in the first resettlement estate in Shek Kip Mei fire catastrophe, Each domestic block was characterised by two wings connected by a bridge where communal sanitary and washing facilities were situated. Because of site constraints, some Mark I blocks were constructed in "I" shape with similar facilities.
1960s The Changes
Slab Block
The Resettlement Department began to convert the early Mark I and Mark II blocks, connecting adjacent units and putting in private kitchens and toilets with lift access to every third floor. This conversion exercise was however found to be uneconomical. After its set-up in 1973, the HA took over and decided to tear down the old buildings and rebuild them into 13-storey blocks with self-contained units. A characteristic of this type of building was the long corridor running the length of each floor.
1970s The Revolution
Twin Towers and Twin H Blocks
The buildings became taller and taller to embark with increasing demand for public housing. The Twin Tower - went up to 20 storeys or more, with a central void to improve air flow. The Twin H design rose to 27 storeys. Both design blocks have lift access to every floor - built with a private balcony / kitchen and a toilet. An air conditioner vent was installed in each flat.
1980s The Evolution
"Y"-shape, Multi-room Unit, Butterfly Estate
The era evolution - Trident and Linear Blocks. Trident Blocks three identical wings in a "Y" shape and shared lifts at the central core built as tall as 34-storey high. Linear Blocks feature multi-room units where partitions can be set up by the tenants. Another unique and interesting block type, the Zigurrat, can be seen on Butterfly Estate (1983). The shape of its buildings just looks like a series of steps.
1990s The Predominant Era
Standard Blocks
The buildings came with standard units of various sizes to cater for different households, and with windows in every room to let in more daylight and air. The extensive use of standardised precast building components such as concrete facades, staircases, drywall panels and semi-finished slabs, facilitated quality control and helped shorten the construction time.
2000s The Present Era
Non-standard Blocks
The feature of these designs is to optimise the use of a site's unique location and to meet residents' needs. The use of micro-climate studies during the planning and design stage results in better ventilation and light penetration for the flats and common areas. At the same time, the adoption of the Universal Design principles ensures the estate facilities cater to the needs of residents of all ages and different physical abilities. This helps to blueprint the "ageing in the community" communal harmony.
Housing Authority was transforming from simply providing basic housing needs to caring for their tenants towards the communities’ overall benefit. As time went on, HA has progressively expanded the implementation of sustainability elements in the design.
Kai Tak Site 1A project design with the application of Carbon Emission Estimation method to benchmark the carbon emission levels throughout the project life cycle
Smart Living in Sustainable Community
Carbon Emission Estimation Life Cycle Assessment framework set up to improve carbon emission reduction for housing developments at the planning and design stages.
Since February 2011, a life cycle Carbon Emission Estimation method has been adopted in all our new development projects during the design stage with domestic blocks design.
"Twin Tanks" water supply installation
Twin-Tank System
Water supply installation provides an uninterrupted fresh and flush water supply to tenants. To achieve more long-lasting, more durable materials such as epoxy-coated reinforcement bars and Grade 45 waterproof concrete be used to build the tanks. All new public rental housing blocks completed from mid-2009 onwards had adopted the installation.
Society as a whole will also benefit as the system is conducive to environmental protection and sustainable development, Jo reviewed.
Estate Ecology
We set out green design guidelines for public housing developments. The tree planting ratio is not less than one tree per 15 flats. We protect the ecology nearby our housing estate carefully by applying balanced ecological planning and design principles in all suitable projects.
Study of vertical daylight factor and indoor environment quality
Micro-climate Studies
With the use of computerised simulation models, we can optimise in our design to enhance wind environment of the site, natural ventilation and daylight for the domestic flats, thermal comfort of external areas and energy efficiency. Since 2004 we have been applying the studies in all public housing projects.
EV Charging Station
Promoting Electric Vehicles
To support Government's policy to promote the wider use of electric vehicles (EVs) for environmental protection, we have provided EV charging facilities in the new carparks and at some parking spaces in the existing carparks on need basis.
200 parking spaces equipped with standard EV charging facilities.
Provision of EVs as contract cars is adopted in the specification for our development projects.
Bio-filtration Units
Air Quality
To reduce air pollutants in car parks and roads, bio-filtration system is on the use.
Zero Irrigation System
Sustainable Urban Drainage System and Sub-irrigation Planting System to reduce water consumption in irrigation.
Green Living Environment
Under the programme "Action Seedling", we encourage participants from residents, schools and community organisations to nurse seedlings plants until they are fit for transplanting into the planters of new public housing estates. The programme aims to unify the inputs from our contractors, tenants and general community in bringing new public housing estates to a greener living environment.
Affordability of the Housing vs “Spade-ready” Sites
High housing price is a very significant issue in HK. The lack of housing affordability in HK is among the most severe in the world. In addition to those who currently cannot afford housing, there are also worries among HK youth that they will not be able to afford their own home in the private market, and thus need to seek for other alternatives - public rental housing.
The biggest obstacle however faced in the provision of public rental housing is a serious shortage of “spade-ready” sites. The official reviewed that most of sites require rezoning and planning applications, followed by major clearance, site formation and infrastructural works. Some also involve first resolving different views of the local community, responding to diverse local demands, securing funding for government-financed works, and even addressing complex site conditions or legal issues involving other developments in the vicinity.
In the past year, 14,300 public rental housing flats were constructed, but we acknowledge that many more are needed. We remain committed to meeting the Government’s ambitious longer-term housing supply target of finding land for and constructing a further 200,000 public rental housing units and 80,000 subsidized sale flats by 2025/26. To achieve such targets, we need to continue working hard, while also soliciting essential support from the local communities for building new flats.
In the present days, to have sustainable community development seems an obvious approach. A healthy mix of sustainable development of the community follows crucial elements as public rental housing, private housing, community infrastructure, commercial facilities that offer employment opportunities etc. These cannot be achieved if the government focuses only on developing public rental housing. In nutshell, a community needs to have diverse land use so that there will be sustainable development and to attain low social costs.
