A number of loopholes will, for instance, mean the city is likely to see apartments with thick glass exterior walls that can be included as part of the saleable area.
Intrusive podiums with car parking space above MTR stations will also still exist unless the Transport and Housing Bureau issues new guidelines to remove them.
Professionals anticipate that the new policy will have little effect in reducing the city's wall effect generated from massive developments.
Exterior walls made of glass and steel, known as curtain walls, were initially designed for commercial buildings but residential designs have increasingly used them in recent years, including the much criticised Queen's Cube project in Wan Chai. But curtain walls - which are 30cm thick and can account for 20 square feet of a flat's saleable area — have not been covered by the new policy announced in last week's policy address.
The new policy states that most green features and amenity facilities should not exceed 10% of a development's total gross floor area to minimise wall effect.
While developers will still be given bonus floor areas for building a curtain wall, they can sell the wall areas to buyers to make lucrative profits — valued at HK$290,000 (RM116,316.71) in the worst case scenario of Queen's Cube given it is sold at HK$14,888 per sq ft.
"Flats with curtain walls may consume more energy as they allow more sunlight in and windows can seldom be opened fully," Hong Kong Green Building Council director Wong Kam-sing said. "It deserves a study to see whether it should be encouraged in residential projects."
Glass-wall designs have become popular in redevelopment projects and new luxury flats, among them: Queen's Cube in Wan Chai, The Oakhill in Happy Valley, Gramercy on Caine Road, Lime Stardom in Tai Kok Tsui, Forfar in Kowloon Tong, The Cullinan in West Kowloon and Hill Paramount in Sha Tin.
Existing policies do not require developers to use glass that effectively filters sunlight. A curtain wall can also exist in any orientation of a building, even if it faces west — a direction that receives most sunlight. It is also stated in land sales conditions that a curtain wall can be exempted from gross floor area calculation. In the case of Queen's Cube, the curtain wall areas account for six to 20 square feet of flats that are sized from 275 sq ft to 307 sq ft in terms of saleable area — which also covers wall, balconies and utility platforms. The redevelopment project, by the Urban Renewal Authority and Nan Fung Group, has been criticised for producing small but expensive flats. The efficiency ratio of the flats — dividing saleable area by gross floor area — is also low.
Because of the large amount of common areas apportioned to a flat, which accounts for 46% of a flat's saleable area, the efficiency ratio only reaches 68%. It will be further reduced to 59% if balconies and utility platforms are excluded from saleable area. The developer did not give an exhaustive list of the common areas apportioned to a flat, but some examples include pump rooms, lift machine rooms, lift and entrance lobbies.
But the trend might change under the new policy to take effect in April, vice-president of the Hong Kong Institute of Urban Design Vincent Ng Wing-shun said. "Architects will be asked to put more facilities inside flats rather than outside, especially inside duplex flats on top floors."
But those necessary but non value-added facilities like pipe ducts, covered walkways and wind catchers that enhance ventilation will be given less space, which might give rise to maintenance problems and a less-friendly pedestrian environment.
Another question mark over the new policy is the government's determination to remove car parks above MTR stations, which hinges on a review by the Transport Department.
A spokeswoman for Development Bureau said the Buildings Department has commissioned a study, covering curtain walls, to look at energy efficiency of building designs. She said the bureau will consider adjusting the policy to cover curtain walls based on the study's findings. The bureau said a comprehensive review of the density on outline zoning plans will be done at a later stage. — South China Morning Post