Type your address. We pull your lot boundary, zone and overlays from the Victorian Government’s land data, place a granny flat behind your house in 3D, and check it against the small second dwelling rules. Free, no sign-up.
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Line the grey box up with your roof in the photo. Distances are from the front and sides of the lot.
Indicative only. Your Planning Property Report and council have the final word. Easement widths and purposes are on the title plan.
Turnkey estimate for this size in Melbourne. A free site visit firms it up: soil, services run, access.
Get a quote for thisIt takes the lot boundary from Vicmap, keeps 2 m off any street side and 1 m off the other boundaries, stays out of easements, and keeps the gap you pick from the house. Then it tries every size and shape that gives the floor area you asked for and picks the squarest one that fits, as far back as it can go.
If nothing fits, it tells you the largest size that does.
A small second dwelling in Victoria can be up to 60 m² without a planning permit in most residential zones, unless an overlay triggers one. It always needs a building permit. In the General and Neighbourhood Residential Zones the lot also has to keep its minimum garden area: 25% for 400–500 m², 30% for 500–650 m², 35% above that.
Since December 2023 most Victorian homes can add a small second dwelling of up to 60 m² without a planning permit. It still needs a building permit, and an occupancy permit before anyone moves in.
This is general information. Your council and building surveyor decide the details for your lot.
Builder price lists in Melbourne in 2026 put a turnkey 60 m² two-bedroom at roughly $190,000–$255,000 including GST. Steel-frame kits start much lower, around $68,000 plus GST to lock-up, but the slab, trades and fit-out come on top.
The things that most often blow a quote out are site costs, not the building:
Ask for these to be priced up front, not as extras after you sign.
Usually not, if it’s 60 m² or less, the lot has an existing house and no overlay applies. You always need a building permit. Lots under 300 m² go through VicSmart, the fast-track permit stream.
Yes, to anyone. The normal rental minimum standards apply, including smoke alarms.
Not on the no-permit pathway. It must not be connected to mains gas.
No. A small second dwelling can’t be subdivided or sold apart from the main house.
The lot boundary, zone, overlays and easements come straight from Vicmap, the Victorian Government’s land data. Your house outline is a guess until you line it up with the aerial photo, and setbacks are simplified. Treat it as a first look before a site visit, not as approval.
Not yet. The land data and the 60 m² rules are Victorian.
We’ll look at your block and come back within one business day. We work across Melbourne.