16.5 Plot Ratio
Plot ratio is a tool to help control the bulk and mass of buildings. It expresses the amount of floorspace in relation (proportionally) to the site area, and is determined by the gross floor area of the building(s) divided by the site area. Plot ratio will apply to both new buildings and extensions to existing buildings.
The gross floor area is the sum of floorspace within the external walls of the building(s), excluding basements but including plant and tank rooms and car parking areas above ground level. In the case of a group of buildings with a common curtilage, the floor areas will be aggregated. The site area includes only such land as lies within the curtilage of the related building.
Plot ratios can determine the maximum building floorspace area or volume on a given site, but on their own cannot determine built form. The same area or volume can be distributed on a site in different ways to generate very different environments.
Consequently, plot ratio standards need to be used in conjunction with other development control measures, including site coverage, building height, public and private open space, the standards applied to residential roads, and parking provision.
Indicative Plot Ratio Standards
The Indicative Plot Ratio standards are set out below:
A higher plot ratio may be permitted in certain circumstances such as:
- Adjoining major public transport termini and corridors, where an appropriate mix of residential and commercial uses is proposed
- To facilitate comprehensive redevelopment in areas in need of urban renewal
- To maintain existing streetscape profiles
- Where a site already has the benefit of a higher plot ratio
- To facilitate the strategic role of institutions such as hospitals