Asbestos always comes out first. Demolishing around it contaminates the rest of the waste stream and turns a contained, quotable job into a site-wide problem that costs several times more to fix.
The sequencing rule, and why it is not negotiable
A demolition that starts before the asbestos is out does three things at once, all of them expensive:
- It contaminates every other waste stream. Clean brick, concrete, steel and timber are all recoverable and cheap to dispose of. Mixed with asbestos, the whole load is asbestos waste, charged by the tonne at a licensed facility.
- It spreads the material across the site. What was a contained item in a known location becomes fragments through the rubble and through the soil — which is a contaminated soil job on top of the demolition.
- It removes the ability to work under controls. You cannot isolate a work area that is now the whole site.
So the order is fixed: survey, then licensed asbestos removal, then clearance where required, then demolition.
The survey comes before the quote
A pre-demolition survey is more invasive than an ordinary inspection, because the building is coming down and there is no reason to leave wall cavities, floor voids and roof spaces unexamined. That is deliberate: the material found before the machine arrives is a line item, and the material found during demolition is a stopped site.
The places pre-demolition surveys most often find material nobody expected: under floor coverings, behind wall linings, in ceiling voids, in the packing around old hot water systems and stoves, in electrical meter boards, and in the eaves of a section that was added later.
Internal strip-outs
Commercial fit-outs are the other half of this work, and the constraint is usually the building rather than the material. The tenancy above is trading, the lift lobby is shared, and the programme has a handover date.
What that changes in practice: the strip-out is zoned so one area is under control while the rest of the floor operates, work often runs out of hours, and no follow-on trade enters a zone that has not been cleared. On friable material — pipe lagging and sprayed insulation are common in older commercial buildings — the area stays sealed until a licensed asbestos assessor issues the clearance certificate. Plan for that in the programme rather than discovering it on handover day.
See commercial asbestos removal for how the staging and documentation work on a trading site.
What comes down, and what is separated
House demolition, garage and outbuilding demolition, internal residential strip-outs, commercial interior strip-outs, and the excavation that follows. Waste is separated on site so the recoverable streams stay recoverable, and the asbestos stream is wrapped, labelled and tracked to a facility licensed to receive it — see asbestos disposal.
The site is left clear, and you get the disposal records for the asbestos stream plus the clearance certificate where the work required one.
Knock-down-rebuild
If you are buying a site to rebuild on, get the asbestos position established before settlement rather than after. A pre-1990 dwelling almost certainly contains it somewhere, and the cost of removing it is a known, quotable number — whereas the cost of discovering it mid-demolition is not. Published ranges are in the cost guide.
