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The General Building Plan submitted to the Building Authority 1. General Building Plan is prepared and submitted to the BA by the Authorized Person. 2. Key aspects to be included in general building plan are:

(a) Density aspects – site coverage, plot ratio (b) Fire safety aspects – means of access for fire fighting and rescue, means of escape

in case of fire, fire resistance and compartmentation (c) Health and environmental aspects – lighting, ventilation, open space (d) Planning issues under other legislation – town planning control, access for person

with a disability, airport height retractions, railway protection 3. Site coverage is the area of the site that is covered by the building. When used to a

composite building consists of both domestic and non-domestic parts, it means the area of site that is covered by that individual part.

4. Plot ratio is the ratio obtained by dividing the gross floor area of the building by the

site area. Gross floor area is the area contained within the outer surface of external walls of a

building, measured at each floor. External finishes and curtain walls may be disregarded in the measurement. Some areas in the building are exempted from gross floor area calculation: examples are main common entrance lobbies, fire refuge areas, water tanks, transformer rooms.

Site area is the total area of the site. 5. The permitted site coverage and plot ratio for each category of site and for various

building height are given in the Building (Planning) Regulations. Sites are classified into 3 categories for permitted site coverage and plot ratio purposes.

Class A site: site abutting on only one street Class B site: site abutting on two streets Class C site: site abutting on three streets (corner site) Examples of permitted site coverage: Non-domestic building (or the non-domestic part of a composite building) not

exceeding 15m above street: 100% site coverage Domestic building abutting on Class A site and over 61m above ground: maximum 33.33% site coverage

Examples of permitted plot ratio: Non-domestic building (or the non-domestic part of a composite building) over 61m above street: 15 Domestic building abutting on Class C site and over 61m above ground: 10

6. However, there may also be restrictions on permitted plot ratio under the lease of the

land. In many cases, plot ratio and site coverage permitted under the lease is less than that permitted under the Buildings Ordinance.

7. Sometimes bonus plot ratio can be given when certain area of the building is dedicated

to the public for passage use. To encourage environmental issues, balconies and external prefabricated walls are also not counted for gross floor area. Bay windows in domestic buildings can also be exempted from plot ratio calculation. Depending on the occupancy need, floor space used for parking may not be countable for gross floor area.

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8. The fire safety requirements on buildings include the provision of adequate means of

escape in case of fire (such as exit routes, staircases, refuge floors in tall buildings), the provision of adequate fire resisting construction (such as the division of building into compartments by fire resisting walls and floors to limit the spread of fire, the fire resisting period of doors and structural elements) and the provision of adequate access for fire fighting (such as emergency vehicular access fire fighting vehicles, fire service installations).

9. Health and environmental aspects in building planning include the adequate provision

of windows, open space between buildings and sanitary fitments. 10. Under the provision of the Buildings Ordinance, the Building Authority may refuse to

approve a building design if he considers that the building would be different in height, design, type or intended use from buildings in the immediate neighbourhood. For example, the BA may refuse to approve a 30 storey building in an area of low-rise houses.

11. In addition to the Buildings Ordinance, building developments are also controlled by the

Town Planning Ordinance to ensure compatibility of land uses. The permitted usage of a site is defined in Outline Zoning Plans for urban area and Development Permission Area Plans for rural areas, prepared by the Town Planning Board. An office building may not be erected on a site defined as for residential use.

12. The Town Planning Ordinance also imposes restrictions to plot ratios lower than that

permitted by the Buildings Ordinance to residential buildings, according to density zoning of the area. For example, maximum domestic plot ratio in Residential Zone 3 may be as low as 3.

13. Under the Hong Kong Airport (Control of Obstructions) Ordinance, there are

restrictions on building height at certain locations in Hong Kong for the safety of aircrafts. The airport height restrictions vary at different locations.

14. Conditions of sale for large-scale development usually contain a requirement for the

submission of Master Layout Plan before the General Building Plan. The main purpose of the Master Layout Plan is to ensure the nature and layout of the large scale development are acceptable to the government.

15 The Master Layout Plan should include information on the formation levels of the site,

arrangements of proposed roads; footbridges and pedestrian ways; location, nature, height and gross floor area of the buildings in the development; vehicular ingress and egress arrangements; parking arrangement; communal open space, landscaping and recreational facilities; and stages of the development.

16. The lease of the land may sometimes contain a clause to restrict the height of a

building to be developed on the site. (H K Ng Jan 2010)