Knockdown rebuild on the South Coast: what it costs and whether it's worth it

Plenty of the best blocks on the coast already have a house on them, usually an older one that no longer suits how people want to live. The question is whether to renovate, or knock it down and start again. Here is how to think about it, and what it costs in 2026.

When a knockdown rebuild makes sense

If the existing home is tired, poorly oriented, or would cost a fortune to bring up to standard, a rebuild often delivers more for the money than a major renovation, and you end up with exactly the home you want rather than a compromise stitched onto an old frame. If the bones are genuinely good, a renovation may still win. We help you weigh it honestly before you commit to either path.

What a knockdown rebuild costs

A knockdown rebuild is two costs: removing the old house, then building the new one. As a guide, demolition of a typical detached home on the South Coast runs from roughly $20,000 to $40,000-plus, more where there is asbestos, difficult access or services to disconnect. The new home is then costed like any custom build, which on the South Coast generally falls between roughly $4,000 and $7,000-plus per square metre depending on the site, the bushfire rating, the finishes and whether services are off-grid. Treat these as indicative ranges, not a quote: the only number that matters is the one for your block and your brief.

Duplex and dual occupancy costs

If the block suits it, replacing one old house with a duplex or dual occupancy can change the maths, whether for investment, downsizing while keeping an asset, or housing family close by. Two dwellings cost more in total than one, but the per-dwelling cost usually comes down through shared services and a single site setup. The planning controls are different too, and we handle those in-house.

Granny flat and secondary dwelling costs

A secondary dwelling, often called a granny flat, is a lower-cost way to add accommodation or rental income without a full rebuild. Costs vary widely with size and finish, but a quality secondary dwelling is a fraction of a new home and can be designed to sit comfortably alongside the main house rather than looking bolted on.

Building from Canberra

A meaningful share of South Coast rebuilds are for Canberra owners replacing an old beach shack on a block they already love. Because we design, approve and build in-house, you do not need to be on site. We manage the whole process at a distance and keep you informed against a clear program.

Getting a real number for your block

Per-square-metre ranges are useful for orientation, but your project is not average. The way to a real figure is a short conversation about your site and your brief, followed by a proper estimate. There is no sales pressure: just a clear picture of what your home is likely to cost before you commit to anything.