New rules proposed to curb wall effect
Public to be consulted on plan for wider gaps between buildings to ensure air flow, writes Olga Wong
New rules requiring wider gaps between buildings will be proposed to reduce the so-called wall effect caused by high-rises blocking air flow, a source close to the government said.
The rules, to be proposed in a forthcoming public consultation, would require 30 per cent of a site's length to be set aside for space between buildings, and 30 per cent of the land area being allocated to landscaping and 'green' features.
There is currently no standard requirement on gaps between buildings, which is usually determined on a case by case basis using air ventilation studies and considering the size of the development. There is also no standard requirement for green features.
The source said care would be taken to prevent developers from profiting from the proposed green space by increasing the overall development density.
The move follows controversy over present arrangements that award bonus floor area in return for incorporating features such as sky gardens, utility platforms and bigger lobbies and corridors that are assumed to improve the quality of life in the developments.
Secretary for Development Carrie Lam Cheng Yuet-ngor said last month the government would consult the public this year on how green features should be incorporated into new developments without increasing the density of the project.
Based on air ventilation studies and overseas examples, a government consultant had advised that leaving 30 per cent of a site's length as gaps would ensure air flow and prevent 'walled buildings'.
'Walled buildings are formed when developers put buildings along the same line to maximise sea views,' the source said.
'To prevent walled buildings, developers would be required to leave at least 30 metres as non-building area if a site is 100 metres long.'
The source said a minimum of 30 per cent green area had been a requirement for developments on the mainland for many years.