A Sydney deck, from the first rule to the last coat of oil
A guide to decks in Sydney in plain words, published by Dotto from the official sources linked on each page. Six guides: when a deck in NSW needs approval, the balustrade rules, bush fire prone land, timber that lasts, termites, and looking after it.
- 1A barrier not less than 1 m above the deck floor. Balustrades
- 2Required where a fall of 1 m or more is possible. Approval
- 3Posts on stirrups above the ground. Timber
- 4A gap between deck and house. Termites
The span table
Six guides, set out the way a span table sets out timber sizes: one row each, read across. Start with the first if you are planning a deck; the last if you already have one.
| No. | Guide | What it answers | Read from |
|---|---|---|---|
| 01 | Do you need approval for a deck? | When a deck in NSW is exempt development, and the two pathways when it isn’t. | NSW Planning Portal |
| 02 | Balustrades and balcony safety | When a barrier is required, how high it must be, the gaps it may have and the rule on climbing. | National Construction Code |
| 03 | Decks in bush fire prone areas | Checking the map, the Bush Fire Attack Levels, and what the RFS asks of a deck. | NSW Rural Fire Service |
| 04 | Timber durability | Durability classes, heartwood and sapwood, treatment levels and fixings. | WoodSolutions and the APVMA |
| 05 | Termites and decks | How the code treats a deck as an attachment, and whose job inspection is. | National Construction Code and NSW Fair Trading’s guide |
| 06 | Deck maintenance | What to check, how often, and how a deck is cleaned and resealed. | WoodSolutions and NSW Government |
Five numbers worth knowing
Each is quoted from its source, with the guide that explains it.
- Exempt decks25 m²
The most floor area an exempt deck in NSW can have, among the standards the Planning Portal lists.
- Height and fall1 m
An exempt deck’s floor can be no more than one metre above existing ground level. The building code requires a barrier not less than 1 m above a deck’s floor where a fall of 1 m or more is possible.
- Openings125 mm
Openings in a barrier, including decorative balustrades, must not permit a 125 mm sphere to pass through.
- Bush fire prone land5 m
An exempt deck on bushfire prone land that is less than 5 metres from a house needs to be constructed of non-combustible material.
- Termites75 mm
WoodSolutions describes deck posts on galvanised metal stirrups with at least 75 mm clearance above finished ground level as one way to achieve termite protection.
Where to check, before anything is built
- Your lot’s zone and planning constraints. The NSW Planning Portal’s Spatial Viewer shows what planning constraints and zoning rules affect a property.
- Whether it is bush fire prone. The RFS’s online tool checks an address on the day you search; the Section 10.7 Planning Certificate from your council confirms it.
- The exempt development standards for decks. On the Planning Portal’s page for balconies, decks and patios.
- The building code itself. Published on NCC Online, where the Housing Provisions set the rules for barriers and termite management.
- An existing deck’s termite protection. The durable notice the code requires, in a prominent place such as the meter box, names the system, its installation date and the recommended inspections.
About this guide
sydneydecks.au is a guide to decks in Sydney, published by Dotto. Each page is written from official and industry sources and links every one of them: the NSW Planning Portal, the Australian Building Codes Board, the NSW Rural Fire Service, Building Commission NSW, NSW Fair Trading, the APVMA, and WoodSolutions.
The rules for a deck in Sydney are NSW rules, and many come from national codes, so every page says which body set the rule it is describing and when that page was checked. Where this guide and an official source differ, the official source is right.
