Good news first: a lot of decks in New South Wales can be built with no council approval at all. Not most jobs we do, but a fair few. The trick is knowing which side of the line your deck sits on before you start, because getting it wrong is expensive to undo.
This is a plain guide to when you can just build, when you need a quick approval, and when you need the full council process, with the actual limits rather than vague hand-waving. It is general information to help you understand the rules. It is not planning advice, and overlays vary block to block, so treat it as a map rather than a guarantee.
The three paths
In NSW, a deck falls into one of three buckets:
- Exempt development. No approval needed. You meet a set of standard rules and you can build. This is the fast, cheap path.
- Complying development (CDC). A fast-track approval. Your deck does not quite qualify as exempt, but it still meets a clear set of standards, so an accredited certifier can sign it off without a full council assessment.
- Development application (DA). The full council process. Your deck does not fit the standard rules, so a council planner assesses your specific proposal and decides.
Most people want the first path. Here is how to tell if your deck qualifies.
Two-minute shortcut: answer a few questions in our deck approval checker and it will tell you which of the three paths your deck most likely falls under. The rest of this guide is the detail behind it.
Can you build with no approval? The exempt rules
To be exempt development, a deck attached to a house has to meet every one of these rules. Miss one and you are out.
- Size: no more than 25 m². And the allowance is shared. The combined floor area of every deck, patio, terrace and verandah on the lot is capped at 15% of the ground floor area of the house on lots larger than 300 m², or at 25 m² total on lots of 300 m² or less. An existing patio eats into the budget for a new deck.
- Floor height: no more than 1 m above the existing ground at any point. On a slope, measure at the highest point, because that is where the rule bites.
- Total height: no more than 3 m above the existing ground at the structure’s highest point.
- Setbacks: at least 900 mm from every lot boundary. In rural and large-lot zones (RU1 to RU4, RU6 and R5) the setback is 5 m.
- Position: behind the building line of any road frontage, meaning no closer to the street than the front wall of the house.
- Walls: any enclosing wall no higher than 1.4 m. Open balustrades and railings are fine; enclosing the deck into a room is a different building entirely.
- Materials: metal components need to be low reflective and factory pre-coloured. On bushfire-prone land, a deck less than 5 m from the house must be built from non-combustible material.
- The land itself. The exempt path is off the table on land on the State Heritage Register or under an interim heritage order, on critical habitat or in a wilderness area, and in foreshore areas. In a heritage conservation area an exempt deck is still possible, as long as it sits behind the building line.
One practical extra that sits outside the planning rules: building over a sewer main or a registered easement needs the asset owner’s sign-off whatever approval path you take, so check where your services run early.
Rule of thumb: a low, open, backyard deck of 25 square metres or less, kept off the boundaries and behind the front of the house, is usually exempt. Lift it up, push it out, or build it big, and you tip into needing approval.
These figures come from the NSW Codes SEPP, the state-wide rule book for exempt and complying development, and are current at June 2026. Planning rules do get amended, so it is worth confirming before you commit; we do exactly that for every deck we design.
A quick example
Say you want a 20 square metre merbau deck off the back door, sitting 300 mm off the ground, a metre clear of both fences, tucked behind the house. That ticks every box, so no approval needed.
Now say you want the same deck, but raised to 1.4 metres to meet a high back door, with a built-in bench right on the boundary. You have broken two rules at once: too high, and too close to the fence. That deck needs an approval.
The fast-track approval: how a CDC works for decks
If your deck misses an exempt rule but still fits the standard rules in the Housing Code, an accredited certifier can issue a complying development certificate without a full council assessment. This is the usual path for raised and larger decks, and it is typically measured in weeks rather than months. The key standards for a deck attached to the side or rear of a house:
- Height is tiered by boundary distance. The deck floor can be up to 2 m above the existing ground if any part of the deck is within 3 m of a side or rear boundary, up to 3 m if it sits 3 to 6 m away, and up to 4 m if every part is more than 6 m away. Above 4 m there is no complying tier, so a high-set deck on a steep block heads to a DA.
- A 12 m² cap for raised decks near boundaries. If the floor is more than 2 m high and the deck is within 6 m of a side or rear boundary, all such structures on the lot are capped at 12 m² combined.
- The lot has to qualify. The Housing Code needs a lot of at least 200 m² that is at least 6 m wide. Lots of 300 m² or less, or narrower than 10 m, use a separate small-lot set of standards with their own numbers.
- The land has to qualify too. Land excluded from complying development includes heritage conservation areas, foreshore areas, environmentally sensitive land mapped in the council plan, land affected by coastal hazards, and high-risk flood land. Other flood-affected land can still get a CDC with an engineer-certified design.
- Zones matter at the edges. The Housing Code covers the residential zones (R1 to R4 and RU5). Rural and large-lot zones run on the Rural Housing Code, which uses different standards.
If that reads like a lot of moving parts, that is because it is. The deck approval checker walks through them in order, or we work it out for you as part of a design quote.
When it is a DA
A development application is the path for decks that do not fit the standard rules: a floor more than 4 m above ground, an undersized lot, or land that is excluded from complying development, like a heritage conservation area or a foreshore block. A DA is not a dead end, just a longer road: a council planner assesses your specific proposal, and a well-prepared application with proper plans gets a fair hearing. High-set decks on steep blocks go through DAs all the time.
We walk through exactly how both applications are lodged in our guide on how to apply for a DA or CDC for a deck.
Not sure which path your deck needs? We’ll check it for free, then design and lodge the approval if there is one. Get a free quote.
The land matters as much as the deck
Two identical decks can land in different buckets purely because of where they are. Bushfire-prone land, flood-prone land, heritage controls and foreshore blocks all carry extra rules, and any one of them can rule out the no-approval path even for a small deck. Plenty of blocks carry one or more of these, so never assume your neighbour’s approval tells you anything about your own block.
The overlays for your lot are listed on a s10.7 planning certificate from your council, and most of them are visible for free on the NSW Planning Portal Spatial Viewer.
What if your deck does not fit?
This is where people ask how to get around the rules. You do not get around them, but you do have real options, and none of them are dead ends.
Option 1: redesign it to fit. Often the simplest fix. Drop the height, pull it back from the boundary, or trim the size, and a deck that needed approval becomes exempt. A good design will look for this first, because it saves you time and money.
Option 2: go the CDC route. If your deck is too big or too high to be exempt but still sits within the standard complying development rules, a certifier can issue a CDC. It is faster than a DA and does not go through a full council assessment. This suits a lot of larger or raised decks.
Option 3: lodge a DA. If your deck does not fit the standard rules at all, for example it is on a heritage block, very high off sloping ground, or close to a waterway, you go through your council with a full development application. It takes longer and needs more documents, but it is the path that handles the trickier sites.
The short version
- A low, open deck of 25 square metres or less, set back from the boundaries and behind the front of the house, usually needs no approval.
- A raised or larger deck usually fits the CDC rules: up to 2, 3 or 4 metres of floor height depending on how far it sits from the boundaries.
- Above 4 metres, on excluded land, or on an undersized lot, it is a DA.
- Not sure? Run the deck approval checker, or ask us.
The honest truth is that working out which bucket you are in, and getting the paperwork right, is the fiddly part. That is something we handle for our customers from start to finish: we design the deck, work out the right approval path, and lodge it for you. If you would rather not wrestle with any of this, tell us about your place and we will sort it out.
Thinking about your own deck? See our decking services or get a free quote.
