What floor space ratio applies to my block?
Written by Shea Cullen, architect, for Dudils.
Floor space ratio (FSR) caps how much floor area a building can have compared with the size of its site. Type an address and the Site Checker reads the FSR for your lot from the Floor Space Ratio Map in your council's Local Environmental Plan (LEP), through the NSW Planning Portal, and shows the lot's area on the same report so you can do the sum.
NSW addresses only. Free, and no sign up.
What is FSR, and how do I work out mine?
FSR is the ratio of a building's gross floor area to the area of its site, written like 0.5:1, and the Site Checker shows the number mapped for your lot. It applies through clause 4.4 of your LEP and its Floor Space Ratio Map, and clause 4.5 sets out how the floor area and the site area are calculated. An FSR of 0.5:1 means the total floor area, across every level, can be up to half the site area.
FSR does not care how the floor area is arranged: 300 square metres on one level and 150 square metres on each of two levels count the same. The footprint is limited separately, by site coverage and landscaped area controls in the DCP or the Codes SEPP.
How big a house can I build on my block?
Multiply the FSR by the site area. On a 600 square metre block with an FSR of 0.5:1 the maximum gross floor area is 300 square metres; at 0.65:1 it is 390 square metres. That figure is a ceiling, not a target. Setbacks, height, landscaped area and private open space often stop a design before FSR does, particularly on narrow or sloping blocks.
Use the registered lot area from the title plan for the sum. The Site Checker shows the registered area when the state's cadastre carries one, and otherwise an area measured from the lot boundary, which can differ by a few square metres from the surveyed figure. On a lot close to a threshold, those few metres matter, so check the deposited plan.
What counts as gross floor area?
Under the Standard Instrument, gross floor area is measured from the inside face of the external walls at 1.4 metres above each floor. It includes mezzanines and habitable rooms in a basement or an attic. It leaves out lift and stair cores, basement storage, plant rooms, car parking needed to meet council's requirements (with the access to it), terraces and balconies with walls under 1.4 metres high, and voids above a floor below.
So a double garage that meets council's parking requirement usually does not count on a DA, but a third car space can. An enclosed balcony counts, and a double height void over the living room does not. Some councils have changed the definition in their own LEP, and the Codes SEPP uses its own definition of gross floor area for complying development, so the same house can measure differently under the two pathways. If you have not chosen a pathway yet, ask whoever draws the plans to calculate both.
What if my block has no FSR?
Then the LEP sets no floor space ratio for your lot, and the size of the house is controlled another way. Many councils leave low density residential land off the FSR map and rely on the DCP's site coverage, landscaped area and setback controls instead, and complying development under the Housing Code applies its own maximum floor area, which rises with the size of the lot.
Not mapped on the report means the map has no number for your lot, never that the house can be any size. Your council's DCP is the next place to look.
Can I build more than the FSR allows?
Only through a development application with a clause 4.6 variation request, which council weighs on its merits and may refuse. The building height page explains how variations work. A complying development certificate cannot go over any standard.
There are floor space bonuses in state policy, such as the Housing SEPP's bonus for developments that include affordable rental housing, but they are written for larger projects rather than a family home.
What does the FSR not tell me?
It tells you the ceiling on floor area, not whether a design will work on the site. It says nothing about where the setbacks fall, how the house meets the slope, how much of the block has to stay as garden, or whether the living areas can face north. Read it with the height limit, the minimum lot size and the slope on the same report, and treat the result as the start of a brief rather than a design.
What floor space ratio applies to my block? Check any NSW address, free.
NSW addresses only. Free, and no sign up.
What else do people ask?
Does a granny flat count towards the FSR?
On a development application, yes: the floor area of every building on the site counts towards the one FSR, a secondary dwelling included. A granny flat approved as complying development follows the Housing SEPP's own floor area limits instead.
Is FSR the same as site coverage?
No. FSR counts floor area on every level. Site coverage measures how much of the land the buildings cover, so a two storey house can have a high FSR and a low site coverage.
Is FSR worked out on the whole lot or on the buildable area?
On the site area, which is generally the whole lot. Clause 4.5 of the LEP sets the rules, including the land that is left out, such as any part of the lot where the proposed development is prohibited.
Where does this information come from?
The Site Checker reads public maps. It is not a section 10.7 planning certificate, a flood certificate, a bushfire attack level assessment or a survey, and a map can be out of date for your lot. Confirm anything you rely on with council or the relevant authority before you buy, design or build. Nothing on this page replaces advice from your certifier, engineer, lawyer or your own designer.