Answer · reviewed 2026-09-29

Do I need council approval to build a deck in NSW?

Short answer

In NSW a deck of up to 25m², no taller than 1m above existing ground level, and at least 900mm (or 5m on rural zoned land) from the boundary can be built as exempt development with no council consent. If it is taller than 1m, enclosed, or over 25m² it needs a complying development certificate or a development application. "Council approval" is planning consent; a separate building permit and NCC compliance still apply to most decks.

Two different approvable things people call "council"

Planning consent (a development application, or the faster complying development certificate) is one thing and is what most people mean by "council approval." Building approval under the Home Building Act / NCC is a different thing and is administered separately. Whether a deck trips the second one cannot be decided by the size alone on the planning side, so a deck that is exempt from planning may still require a building permit and an occupation certificate. Treating the two as the same is how homeowners end up with a deck they built but cannot legally sell or insure.

The exempt-development test, in numbers

Maximum deck area	25m²
Maximum floor height above existing ground	1m
Maximum height at any point	3m above existing ground level
Clearance from lot boundary	900mm (5m on rural RU zones)
Total all such structures on the lot	15% of ground floor area (>300m² lot), or 25m² (lot ≤300m²)
Enclosing wall, if any	no higher than 1.4m
Location	behind the building line of any road frontage

A deck that satisfies every one of these is exempt development: no need to lodge a DA, and in many cases no need to pay council at all. These are the state-level standards in the Codes SEPP as set out in the NSW Government fact sheet; individual LEPs and DCPs can add limits, so the state minimum is not a guarantee.

If it does not qualify, two faster-or-slower paths

A deck that is too tall, enclosed, or over 25m² is not exempt. It can still be approved without a full DA as a complying development, where a CDC certifier issues the certificate in about four working days once the standards are met, and it is typically cheaper and faster than a DA. If it trips a standard that CDC cannot accommodate, or the site is in a controlled zone such as a heritage, foreshore or bushfire-prone area, the only path is a development application, which goes through the public comment period and can take several months.

The 1m is the number that decides

Most decks that need council approval fail on one line: the finished floor level over 1m above existing ground. A garden-level deck is nearly always exempt if it is under 25m² and set back; the moment you build up for a view, privacy or to reach back-door height, the deck falls into CDC or DA territory. "Above existing ground" means the undisturbed level before any earthworks, so grading the site to lower the apparent height does not move the exemption test.

Where you build shifts the answer

A deck that is compliant by the numbers can still need a full DA if it sits in a foreshore area, on bushfire-prone land, inside a heritage item or local heritage area, or over a flood level. The Codes SEPP excludes exempt development from several of these contexts, and the 2021 Illawong decision is a useful public example of a steel deck ordered demolished for extending into a foreshore area under an LEP building line.

What to confirm before you order the timber

Ask a CDC certifier, not the deck builder, to confirm in writing whether your specific deck is planning-exempt or needs a CDC/DA (they are the ones who can certify), and separately confirm the building permit position under the NCC including the balustrade height rule (balustrading is a building-code matter and applies from a fall height well below the 1m planning-exemption threshold). Get both answers in writing before the site is broken open, because once unapproved work has been built, the options narrow to demolition or retrospective approval on the council’s terms.

Sources

Balconies, decks and patios – Rules for exempt development, NSW Government (Department of Planning and Energy / Planning Portal). Checked 2026-09-29.
Balconies, Decks and Patios (exempt development pathway), NSW Planning Portal. Checked 2026-09-29.
State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, NSW Legislation. Checked 2026-09-29.
J. Solomon Pty Ltd v Sutherland Shire Council [2021] NSWLEC 1793, NSW Land and Environment Court. Checked 2026-09-29.

Government fees are quoted from the government source. Market prices are the observed spread across the guides listed, not our estimate. Prices change; the checked date is when a human last looked.

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