The Home Construction guide explains how a new home is built in NSW. A knockdown rebuild follows the same build, with a demolition and some extra checks in front of it. This page sets out the order.
What is a knockdown rebuild?
A knockdown rebuild (often shortened to KDR) means demolishing the house you own and building a new one on the same lot. You keep the land, the location and the neighbours; you replace a house that no longer works rather than renovating around its problems.
What are the steps in a knockdown rebuild?
- Site assessment: zone, lot size, slope, trees, services, easements, and any bushfire, flood or heritage mapping. A section 10.7 planning certificate from council lists most of it.
- Design and price: the new home is designed for the block, and the builder prices it, including demolition and site costs.
- Approval: a complying development certificate (CDC) or a development application (DA), with a BASIX certificate for the new home. Demolition is usually approved in the same application.
- Contract and insurance: a written contract with a licensed builder and, for work over $20,000, a Home Building Compensation Fund certificate before work starts or any payment is taken.
- Demolition: services are disconnected, any asbestos is removed by a licensed removalist, and the house comes down. House demolition in NSW covers this step.
- Construction: the same stages as any new home, set out in stages of a new home build, with mandatory inspections by the certifier.
- Occupation certificate and handover: the certifier issues the occupation certificate, and you move back in.
What has to be in place before the old house comes down?
Approval, a signed contract, the insurance certificate and somewhere to live. Demolishing early, before the new home is approved, leaves an empty lot that may still need design changes. The other common surprise is the services: water, sewer, power and gas all need to be disconnected and capped before demolition, and reconnected for the new house.
Should a knockdown rebuild go through a CDC or a DA?
A CDC is the faster pathway where the new house meets every standard in the relevant state code: NSW Planning publishes approval times for complying development of as little as 20 days. A DA is needed where the design or the land does not fit the code, for example on some heritage, bushfire or flood-affected land. On steep Illawarra blocks the site often decides the pathway; Building on the Illawarra Escarpment covers those constraints.
Is a knockdown rebuild worth it?
It usually is when the house needs work everywhere at once (structure, wiring, plumbing, layout) and the block and location are what you want to keep. It is less clear-cut when only one or two rooms are the problem. How long the whole process takes is covered in how long a knockdown rebuild takes.
If you are rebuilding in the Illawarra, start with a site visit from a knockdown rebuild builder based in Wollongong before you pay for design, so the demolition, site costs and approval pathway are known from the start. Check any builder's licence and insurance first: choosing a builder shows how.
Sources
Checked on 25 October 2026.
- NSW Department of Planning, Complying development: definition and published approval times.
- NSW Planning Portal, BASIX: a BASIX certificate for a new home.
- icare, What is icare HBCF and why do I need it?: the certificate before work starts or any payment.
- NSW Government, General building work: contractor licence required above $5,000 in labour and materials, including GST.
- NSW Government, What certifiers do: mandatory inspections and the occupation certificate.
General information from a builder, not legal or planning advice. Confirm current requirements with your council, certifier or Building Commission NSW.