Engadine 2233 · Sutherland Shire
Home Extensions in Engadine: Family Room or Outdoor Room?
Half the family rooms I'm asked to build should really be outdoors.
Engadine backs onto the Royal National Park. People move here for the bush and the air, then spend their weekends inside a 1970s lounge with the curtains shut. Before you enclose more floor, it's worth asking whether the space you want has walls at all.
Short answer
Should an Engadine home extension be a family room or an outdoor room?
If you'd mostly use it from spring to autumn, a roofed outdoor room costs far less per m² than an enclosed extension. For year-round use, enclose it: framed additions of 50 to 75m² run $1,690 to $1,825 per m² in Sydney. Bushfire ratings apply to attached structures. Sutherland Shire DAs take 11 to 15 weeks, complying development 15 to 25 working days.
Written and reviewed by Oliver Alameri
Licensed builder, NSW Contractor Licence 487805C · Founder, Buildana
Fact-checked
Room or roof: the real difference
An enclosed extension is a habitable room. It needs insulation, compliant glazing, lighting, heating and cooling, and it counts toward the energy targets. It's floor area in every sense, including on the valuation.
A roofed outdoor room is a different animal. Posts, beams, a roof, a good floor, maybe a kitchen along one side. No thermal envelope, no curtains, far fewer trades. Per square metre it's much cheaper, and in Engadine it's used for more months of the year than people expect.
What decides it? Mostly how you live. Kids who want a rumpus in July need walls. A family that eats outside from September to April probably doesn't.
- Enclosed room: year-round, adds floor area, costs more
- Outdoor room: seasonal, lighter build, faster approval
- Hybrid: an outdoor room now, framed so it can be enclosed later
The cheapest square metre is the one you don't have to heat.
Opening roofs, and why wind matters
Motorised aluminium louvres are the popular choice here. Closed, they shed rain. Open, they let winter sun into the rooms behind. A rain sensor shuts them without anyone touching a button.
They're heavier than a plain skillion and they catch wind, so the posts, beams and fixings need engineering for the site's wind rating. Gutters too. A big roof dumps a lot of water in one place, and that water needs a proper connection into stormwater, not a splash onto the lawn.
Near the bush, material choice changes. A structure attached to the house is generally treated as part of it under the bushfire standard, so on BAL-rated lots expect non-combustible posts and framing, or timber species rated for the level.
Not sure it needs walls?
Send me your Engadine address plus some phone shots of the rear yard. I'll sketch both options roughly and tell you what each would cost to build.
0476 300 300Posts on sandstone
Engadine sits on Hawkesbury sandstone. For a new enclosed wing that can mean rock cutting to get a level slab, which is slow and loud. For an outdoor room, it's mostly good news. Pad or bored footings down to rock hold posts beautifully, and a deck or suspended slab can sit over the fall instead of cutting into it.
The catch is the rock line. On some blocks it's at the surface, on others a metre down under sand. A couple of probes before design tells you which.
Approvals and cost in the Shire
Small pergolas and decks can sometimes be exempt, inside strict limits on size, height and distance from boundaries. Most roofed outdoor rooms of useful size aren't. Code-compliant work gets a complying development certificate in about 15 to 25 working days; anything outside the code goes to Sutherland Shire as a DA, typically 11 to 15 weeks. Bushfire-prone land adds a report to either path.
For an enclosed room, Rawlinsons prices a timber-framed single-level addition of 50 to 75 square metres at $1,690 to $1,825 per square metre for Sydney, with no local loading applied for Engadine. Brick veneer runs $1,825 to $1,965. An outdoor room comes in well under both, but it varies so much with roof type and kitchen that I price it from the design, not a rate card.
Deciding between the two
Questions I'd put to any Engadine family before drawing either.
- 01
How many months a year would you realistically use it?
- 02
Do you need it for sleeping, study or winter rumpus space?
- 03
What BAL rating does your lot carry?
- 04
Where does the roof water go?
- 05
How far down is the rock?
- 06
Could an outdoor room be framed to enclose later?
Extensions and outdoor rooms in Engadine
Is an outdoor room cheaper than an extension?
Usually by a wide margin per square metre, because there's no insulation, glazing or heating, and fewer trades are involved.
Do opening roofs leak?
Good louvre systems shed rain well when closed. Leaks usually come from poor gutters or junctions with the house, so detailing matters.
Does bushfire rating affect a pergola?
It can. Structures attached to the house are generally treated as part of it, so materials must suit the lot's BAL.
Can I enclose an outdoor room later?
Yes, if it's designed for it: footings, roof and floor levels planned for walls, and the approval pathway checked at that stage.
Sources and references
Costs are from the Rawlinsons handbook with the local cost index applied; rules and timeframes are checked against the sources below.
More life behind the kitchen door.
An Engadine extension or outdoor room designed around how you actually live.