The knockdown rebuild process has seven steps. This page looks at them by time: which take longest, which are predictable, and which depend on you.
How long does each stage take?
| Stage | What sets its length |
|---|---|
| Site assessment and feasibility | Surveys, planning certificate, and how quickly decisions are made |
| Design and selections | How many design rounds, and whether selections are made before pricing |
| Approval | CDC (published times of as little as 20 days) or DA (council assessment, longer and less predictable) |
| Contract, insurance, finance | Lender valuations and the insurance certificate |
| Demolition | Asbestos, services disconnection and access |
| Construction | Size, slope, weather, inspections and variations |
| Occupation certificate | Final inspection and any outstanding items |
Which parts does the owner control?
- Decisions: design sign-off and selections. Late selections and changes are the most common owner-side delay.
- Pathway: a design that fits the complying development code can be approved much faster than one that needs a DA.
- Variations: every change after the contract adds time. The provisional sums page explains why allowances matter here too.
What stretches a knockdown rebuild in the Illawarra?
- Slope: geotechnical reports, engineering and retaining add design and construction time on escarpment blocks.
- Bushfire and flood mapping: they can rule out the fast CDC pathway and add reports to a DA.
- Trees: protected trees may need a permit or arborist report.
- Weather: wet periods stop excavation and slab work.
- Asbestos: licensed removal must be notified to SafeWork NSW before it starts.
The sloping blocks guide covers the slope factors in detail.
How should you plan the move out?
Plan to move out at demolition, not at approval, and keep the lease flexible at the far end, because construction is where weather and variations add weeks. Ask the builder for a staged program with the approval and construction periods shown separately, and check that the contract says how delays are handled.
For a realistic program on your own block, talk to a Wollongong knockdown rebuild specialist after a site visit, not before: the slope, access and approval pathway decide most of the time.
Sources
Checked on 25 October 2026.
- NSW Department of Planning, Complying development: definition and published approval times.
- NSW Government, What certifiers do: mandatory inspections and the occupation certificate.
- NSW Government, Contracts for residential building work: written contracts, progress payments and variations.
- SafeWork NSW, Notify SafeWork NSW: notice before removing friable asbestos or more than 10 m² of non-friable asbestos.
General information from a builder, not legal or planning advice. Confirm current requirements with your council, certifier or Building Commission NSW.