Free quick guide

How much can I build on my lot? NSW complying development calculator

Enter your lot frontage, depth and area to see the indicative floor area, landscaped area, setbacks and height a certifier would check under the NSW Housing Code, for a new house, an extension, a granny flat or a duplex.

Residential lots only. This calculator is a general information tool for houses, extensions, granny flats and side by side duplexes on residential land in NSW. Complying development may not be available on your lot because of zoning, heritage, bushfire, flood, easements, covenants or other land exclusions, and the controls change often. Treat the result as a quick guide that needs a proper review.
  1. Your lot
  2. The site
  3. Your result
Your lot and project

Use the area on your deposited plan or contract if you have it. If you only enter frontage and depth, we multiply them.

How complying development limits what you can build

Complying development is the fast-track approval in NSW: if a house, extension, granny flat or duplex meets every standard in State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, a council or registered certifier can approve it with a complying development certificate (CDC) instead of a development application. There is no site coverage control in the Housing Code. Instead, how much you can build is set by the maximum gross floor area for your lot size (clause 3.9), the minimum landscaped area (clause 3.13), the setbacks (clause 3.10) and the 8.5 m height limit (clause 3.8). Granny flats follow Schedule 1 of State Environmental Planning Policy (Housing) 2021, and side by side duplexes follow the Low Rise Housing Diversity Code (Part 3B).

Maximum gross floor area under clause 3.9 of the Housing Code

Lot areaMaximum gross floor area of all buildings
200 to 250 sqm78% of lot area
Over 250 to 300 sqm75% of lot area
Over 300 to 350 sqm235 sqm
Over 350 to 450 sqm25% of lot area + 150 sqm
Over 450 to 560 sqm290 sqm
Over 560 to 600 sqm25% of lot area + 150 sqm
Over 600 to 740 sqm335 sqm
Over 740 to 900 sqm25% of lot area + 150 sqm
Over 900 to 920 sqm380 sqm
Over 920 to 1,000 sqm25% of lot area + 150 sqm
Over 1,000 sqm400 sqm

For a battle-axe lot, the area of the access laneway is excluded when calculating lot size (clause 3.9(2)). Sourced from the New South Wales Legislation website at 29 October 2026. For the latest information on New South Wales Government legislation please go to https://www.legislation.nsw.gov.au.

Frequently asked questions

How much can I build on my lot under complying development in NSW?

Under the Housing Code, the maximum gross floor area of all buildings depends on lot area: 78% of the lot for 200 to 250 sqm, 75% for over 250 to 300 sqm, then fixed amounts or 25% of lot area plus 150 sqm, up to 400 sqm for lots over 1,000 sqm (clause 3.9). Landscaped area, setbacks and the 8.5 m height limit also apply.

Is there a site coverage limit under the NSW Housing Code?

No. The Housing Code controls bulk through maximum gross floor area, minimum landscaped area (10% to 45% of the lot depending on lot size), setbacks and an 8.5 m height limit, rather than a site coverage percentage.

What is the minimum lot size for complying development for a house?

Under the Housing Code the lot must be at least 200 sqm and at least 6 m wide at the building line, in zone R1, R2, R3, R4 or RU5. Battle-axe lots must be at least 12 m by 12 m excluding the access laneway, with a laneway at least 3 m wide.

Can I build a granny flat as complying development?

Generally where the lot is at least 450 sqm (excluding any access handle), the frontage is at least 12 m for lots up to 900 sqm, and the secondary dwelling is no more than 60 sqm, under the Housing SEPP. Land exclusions and the Schedule 1 standards must also be met.

Can a duplex be complying development?

A side by side dual occupancy can be complying development under the Low Rise Housing Diversity Code where the LEP permits it, the lot is at least 400 sqm (or the LEP minimum if larger) and generally at least 15 m wide, and the design meets the code and its design guide.

Is the calculator result an approval?

No. It is a general information quick guide. Whether complying development is available depends on the full codes, your planning certificate, land exclusions and site conditions, which need a professional review.

Disclaimer. The calculator and this page are general information prepared by the URBA Planning Team from publicly available NSW Government sources. They are not planning, legal or financial advice and do not confirm that complying development is available for any lot. Results depend on the information you enter and on standards that are amended regularly; controls can differ for individual lots because of land exclusions, Schedule 5 maps, council variations, covenants and site conditions. Figures must be confirmed against the instruments in force and by a qualified planner or registered certifier before any design, purchase or lodgement decision. Legislation extracts are reproduced under the NSW Legislation website's Creative Commons Attribution 4.0 licence; the Department's guide is linked, not reproduced. URBA Planning, a division of Contrive Consultants Pty Ltd, accepts no liability for any loss arising from reliance on the calculator.