The whole sequence, in order
Most people picture a knock-down rebuild as demolition, then building. The demolition is actually a short event surrounded by a lot of preparation, and the preparation is where the timeline lives.
- Site investigation. Survey, soil test, service locations. Some of this feeds the demolition scope and all of it feeds the build.
- Design and builder selection, running in parallel with everything below.
- Planning certificate — establishes the demolition approval pathway.
- Hazardous materials survey if the house is pre-1990. In the Illawarra, assume it is needed.
- Demolition approval lodged — CDC or DA depending on the property.
- Service disconnections initiated. Start these early; electricity abolishment is the long pole.
- Asbestos removal by a licensed removalist, if the survey requires it.
- Demolition — two to four days.
- Site left to the agreed standard.
- Building approval and construction.
Steps 3 through 7 overlap heavily. Run sequentially they take months; run in parallel, four to eight weeks is realistic for a straightforward house.
The three things to agree with your builder first
This is the part that saves the most money, and it happens before the demolition is even quoted.
What level should the block be left at? "Cleared" is not a standard. A block ready for a surveyor to peg is a different finish to a block that simply has no house on it. Get a nominated level or a clear written description into the demolition scope.
Does the slab go, and to what depth? In a rebuild, almost always yes — but say so, and include the footings and edge beams. Those sit below the visible slab and are the single most common thing discovered by whoever excavates next. Concrete removal covers how it is priced.
What stays? Retaining walls, fences, established trees, the driveway, a shed you want to keep. Every one of these is a scope decision, and each is expensive to reverse. Trees in particular are a separate approval and cannot be removed under a demolition consent.
Getting these three into the demolition quote costs nothing. Discovering them afterwards costs a variation at a point where the machine has already left.
Where the weeks actually go
| Stage | Realistic duration |
|---|---|
| Planning certificate | days |
| Hazardous materials survey | 1–2 weeks including lab time |
| Demolition approval (CDC) | weeks |
| Demolition approval (DA) | considerably longer |
| Service disconnections | 3–6 weeks, electricity longest |
| Asbestos removal + clearance | 1–2 weeks where required |
| Demolition itself | 2–4 days |
The demolition is the shortest item on the list. Everyone plans it and underestimates the rest.
The Illawarra specifics
Access sets the price. The narrow strip below the escarpment produces genuinely constrained sites — Thirroul, Bulli, Corrimal and the older parts of Wollongong and Port Kembla. Smaller machines, more truck movements, sometimes street loading under permit. Newer land through Dapto, West Dapto and Shellharbour is far more straightforward and prices accordingly.
Assume asbestos. The post-war fibro housing across the region means a pre-1990 house should be treated as containing asbestos until a survey says otherwise. This is the biggest single variable in both cost and program. See asbestos in Illawarra homes.
Five councils, five processes. Wollongong, Shellharbour, Kiama, Wingecarribee and Shoalhaven each have their own controls. Advice from a job in one does not transfer to another.
Growth-area covenants. On newer estates, developer design guidelines can sit alongside the council process.
Capture the site information while you can
Once the house is down and before the new work starts, the site is more legible than it will ever be again.
Photograph and record the sewer junction position, the water main entry, the electricity point of attachment, and the levels. Keep the survey. Keep the hazardous materials report and the asbestos disposal documentation.
That file costs nothing to assemble and saves real money at the build stage — and a future buyer's inspector may well ask for the asbestos records.
The neighbours
On tighter Illawarra blocks the adjoining house can be very close. Expect hoarding along shared boundaries, protection or removal of shared fencing, dust suppression, and often a dilapidation report on adjoining properties before work starts.
That report is a documented record of the neighbour's existing condition, and it protects you as much as them. Without one, any pre-existing crack next door can become your problem.
Tell the neighbours what is happening and roughly how long it will take. It costs nothing and prevents most of the disputes that arise on residential demolition.
The costs people forget to budget
Beyond the demolition and the build, a knock-down rebuild carries a set of intermediate costs that surprise first-timers.
Somewhere to live. The gap between moving out and moving in is longer than the construction program, because it includes the demolition lead time at the front and the finishing at the back. Rent for that period is frequently the largest unbudgeted item in the whole project.
Storage. For whatever does not come to the rental.
Two lots of moving. Out, and back in.
Holding costs. Rates, insurance and any loan interest continue on a block with no house on it.
Site costs at the build stage. Soil conditions, levels and service positions can all add to the slab and footing costs, and they are only fully known once the block is clear.
None of these are demolition costs, but they all sit inside the demolition timeline, which is why compressing the lead time has value beyond convenience.
Finance and insurance during the gap
Two administrative items sit awkwardly in the middle of a knock-down rebuild and are easy to overlook.
Insurance. Once the house is gone you are insuring vacant land, not a dwelling, and then a construction site. Those are different policies. Tell your insurer before the demolition rather than after, and check who carries the risk during the demolition itself — the contractor's public liability covers their work, not your land.
Finance. If there is a mortgage, the lender has security over a property that is about to have its main improvement removed. Construction loans handle this routinely, but the lender needs to know the plan, and the drawdown schedule usually keys to build stages that only start after demolition.
Neither is difficult. Both are much easier to arrange in advance than to explain afterwards.
One decision worth making early
Decide whether you are demolishing to rebuild or demolishing to sell. It changes the scope.
A block being sold wants to look presentable and be safe — level, clear, tidy, fenced. A block being built on wants to be at a nominated level with the slab and footings gone, services identified, and clean enough for a surveyor.
They are different finishes at different prices, and the second is not automatically included in the first. Say which one you are buying.
Getting a price
The cost bands cover the numbers, how quotes are built covers reading one, and house demolition covers the work itself.
Call 02 4214 4202 or send the site details through — and if you have a builder already, tell us what they want the block to look like.
More from Demolition Guides
- Asbestos in Illawarra homes: how to tell and what to doWhy so much Illawarra housing contains asbestos, where it hides, how it is identified, who may lawfully remove it, and what it does to a demolition program.
- CDC or DA? Which demolition approval you needThe two NSW demolition approval pathways explained, what takes a property out of complying development, and why nobody can promise you an outcome.
- Class A vs Class B asbestos licences explainedThe difference between friable and non-friable asbestos, which NSW licence class covers each, and how to check a removalist holds the right one.
- What it costs to demolish a house in NSW2026 house demolition cost bands for NSW and the Illawarra, the five variables that move the number, and the lines cheap quotes leave out.
Frequently asked questions
How long does the demolition stage of a knock down rebuild take?
Two to four days on site for a typical house. The realistic lead time in front of it is four to eight weeks, covering the approval pathway, service disconnections and any asbestos removal. Those run in parallel, which is what keeps the total down.
Should the slab come out?
Almost always in a rebuild, because the new structure needs its own footings and the old slab is in the way. Confirm it explicitly in the demolition scope, and confirm the footings and edge beams are included too — those are the classic omission.
What level should the block be left at?
Whatever your builder specifies. This has to be agreed before the demolition is quoted, not after. 'Cleared' and 'level to a nominated height, ready for a surveyor to peg' are different standards at different prices.
Can demolition and the building approval run at the same time?
Frequently, yes, and it is usually the right approach. Demolition often has its own approval pathway separate from the new dwelling, so the block can be cleared while the building design is finalised or assessed. Confirm the sequencing with your certifier.
What about the driveway and the crossover?
The driveway inside the boundary is part of the demolition scope if you want it gone. The crossover between the boundary and the road usually sits on public land, carries council requirements and is often handled at the building stage rather than the demolition one.