LCQ5: Green features of new residential buildings

Following is a question by Dr the Hon Chiang Lai-wan and a reply by the Secretary for Development, Mr Michael Wong, in the Legislative Council today (June 23):


In order to encourage developers to adopt green building concepts, the Government implemented a policy on green and innovative buildings in 2001 to allow green features such as balconies, communal podium gardens and sky gardens to be exempted from the calculation of the gross floor areas (GFA) of residential development projects. The Government revised the relevant arrangements in 2011 by stipulating that the area of balconies that may be exempted be reduced from 100 per cent to 50 per cent at the most. It is learnt that developers have since then reduced the provision of balconies or only provided very small balconies known as "utility platforms" for new residential units. In this connection, will the Government inform this Council:

(1) given that global warming is getting increasingly serious and various countries are striving to reduce carbon emissions, whether the Government will consider encouraging the provision of communal rooftop sky gardens in eligible new buildings for greening purposes; if so, of the timetable; if not, the reasons for that;

(2) given that green balconies can make homes better ventilated and help absorb carbon dioxide and release oxygen, whether the Government will require that new residential units must be provided with green balconies, that such balconies may only be used for greening purposes, and that the area of balconies may be fully exempted from the calculation of GFA but may not be included in the calculation of the saleable areas stated in sales documents; if so, of the details; if not, the reasons for that; and

(3) whether it knows the respective cities in the world with level of development comparable to that of Hong Kong whose governments have currently required that new residential buildings must be provided with balconies or communal rooftop sky gardens, or implemented measures to encourage developers to provide such facilities, as well as the reasons for implementing the relevant policies?


The Government has been adopting a multi-pronged strategy to promote construction of green buildings, encourage innovation in building technology and reduce carbon emissions so as to combat climate change. The Government grants gross floor area (GFA) concessions to green and amenity features and essential features to encourage developers to provide the same in new development projects.

In 2009, in response to public concerns over the quality and sustainability of the built environment, the Government has launched in collaboration with the Council for Sustainable Development (SDC) a public engagement process entitled "Building Design to Foster a Quality and Sustainable Built Environment", with a view to reaching a consensus with various sectors of the community through in-depth discussions on the matter.

Having thoroughly considered the recommendations of the SDC after the above public engagement exercise, the Government has introduced a series of measures since April 2011, including the promulgation of Sustainable Building Design Guidelines (SBDG) to foster a quality and sustainable built environment in Hong Kong. The guidelines require the incorporation of design elements, viz. building separation, building setback and site coverage of greenery, in new buildings. In so far as the Buildings Department (BD) is concerned, to implement these design elements, whether a development project has complied with the SBDG will be a consideration factor in deciding if GFA concessions may be granted, where applicable (e.g., for sites reaching certain size).

Besides, to contain building bulk and reduce the adverse environmental or visual impacts to its surrounding areas, the 2011 policy has tightened the GFA concession arrangements, including lowering the level of concessions for car parks, balconies and utility platforms, and imposing an overall cap of 10 per cent on GFA concessions. The BD, the Lands Department and the Planning Department have through the Joint Practice Notes (JPN) set out the design criteria for granting GFA concessions of green features (such as balconies, utility platforms and communal sky gardens for residential buildings).

Having consulted the Environment Bureau and the Transport and Housing Bureau (THB), my reply to the three parts of the question is as follows:

(1) Under the SBDG policy introduced in 2011, GFA concessions may be granted for certain green and amenity features which have fulfilled the building design requirements for building setback, site coverage of greenery, etc. Specifically, recognising the environmental benefits brought by communal sky gardens, full GFA concession may be granted if such feature meets the criteria set out in JPN No. 1 and Practice Notes for Authorized Persons, Registered Structural Engineers and Registered Geotechnical Engineers APP-151 and APP-152 issued by the BD. The exempted area will also not be subject to the overall 10 per cent cap on GFA concessions.

(2) To encourage the provision of balconies in residential buildings, if the balcony meets the criteria set out in JPN No. 1, 50 per cent of its area may be exempted from GFA calculation. Such exempted areas will however be subject to the overall 10 per cent cap on GFA concessions.

The current arrangement has taken into account the fact that the balcony of an individual flat is generally for exclusive use by the occupants. It has also balanced the views on controlling building bulk collected in the aforesaid public engagement exercise. According to the consultancy study engaged by the BD, 80 per cent of the residential development projects completed in 2015 to 2017 with GFA concessions granted on green and amenity features were provided with balconies. It reflects that the current incentive for provision of balconies through granting GFA concessions is to a certain extent effective.

Since 2019, to further facilitate the maintenance of air-conditioners (AC) installed at the exterior of buildings, the BD has accepted an AC platform to combine with a balcony and/or a utility platform. The arrangement encourages flexible design and provides better maintenance access to ACs. The Government will continue to review the requirements for green and amenity features from time to time to encourage such provisions in green buildings.

The THB advised that the Residential Properties (First-hand Sales) Ordinance (the Ordinance) aims at enhancing the transparency and fairness in the sales of first-hand residential properties. The Ordinance provides for the definition of saleable area and sets out a uniform standard for prospective buyers to calculate the average price per square foot of different flats and developments. At present, the area of balconies is included under saleable area.

(3) To further promote green buildings, the BD has commissioned a consultant to review the measures for granting GFA concessions. According to the consultant, GFA concessions have been granted in Singapore and some cities in the United States (US) as incentives to promote green buildings and enhance the overall built environment. The consultant pointed out that green building elements promoted vary in different regions. For example, in Chicago of the US, the measures concerned are mainly adopted to promote green roofs, while those adopted in Singapore seeks to promote various features such as greening and outdoor sitting out areas.

As regards Hong Kong, upon in-depth studies and full engagement with the industry, the consultant recommended that the current overall cap on GFA concessions be maintained at 10 per cent. In addition, the consultant recommended tightening the prerequisite by requiring new private development projects to achieve a specific rating under the Building Environmental Assessment Method Plus (BEAM Plus) in order to apply for GFA concessions for green and amenity features. If a project can only attain a lower rating, it has to demonstrate compliance with one or more new specific standards which promote a quality and sustainable built environment. Examples of which include extensive greenery application, application of precast modules, better interior natural ventilation and elderly-friendly facilities. We believe that this performance-based approach will promote green and low-carbon buildings in a more flexible and effective manner, which complements our target to achieve carbon neutrality before 2050 in Hong Kong. The BD is working closely with the stakeholders to formulate the implementation details of the proposal with an aim to launch it in 2022.

Thank you, President. 

Ends/Wednesday, June 23, 2021
Issued at HKT 16:38