On a knockdown rebuild, the demolition is the first real work on site, and it sets up everything that follows. A rushed demolition can leave asbestos in the soil, damage the house next door or hold up the start of the new build. Here is what to sort out first.
Does the demolition need approval?
In NSW, only small structures that could themselves be built as exempt development, such as a minor shed or deck, can usually be removed without approval. Demolishing a house generally needs one of these:
- a complying development certificate (CDC) under the Demolition Code, often issued with the CDC for the new home
- a development application (DA) to council, which can cover the old house's removal and the new build
Heritage items cannot be demolished under the codes. In heritage conservation areas, the codes allow only limited demolition, such as internal elements, outbuildings and house walls that do not face the street. If your property has a heritage listing, expect to go through council.
Asbestos: assume it is there until proven otherwise
SafeWork NSW advises that a house built before the late 1980s may contain asbestos. It can turn up in wall and eave sheeting, wet area linings, roofing, vinyl floors and old pipes. Have a licensed assessor or other competent person inspect the house and identify the asbestos before demolition is planned.
Who can remove it comes down to the type and the quantity:
- Friable asbestos, which crumbles by hand when dry, needs a licensed removalist to take it out, whatever the quantity.
- Non-friable (bonded) asbestos over 10 m² needs a licensed removalist. A Class B licence covers this work.
- Small quantities of bonded asbestos may legally come out without a licence, though SafeWork NSW recommends a licensed professional for any amount.
After removal, a clearance certificate confirms the area is safe. For friable asbestos it must come from an independent licensed asbestos assessor. Keep a copy, because the certifier and the builder will both want it.
Conditions you will see on a demolition approval
The exact conditions depend on the approval, but common ones include:
- giving the principal certifier a waste management plan before work starts
- putting erosion and sediment controls in place before demolition and maintaining them
- working only within set hours, usually with no demolition on Sundays or public holidays
- carrying out the work following AS 2601, the national demolition standard
- notifying neighbours before demolition starts
- getting an engineer's report where a wall close to the boundary adjoins a wall on the neighbour's lot, and weatherproofing any exposed shared wall
- removing old swimming pool pipework and filling the pool area with compacted fill
Services and safety on the day
Licensed tradespeople must disconnect gas, water, sewer, electricity and telecommunications before demolition starts. Plans of underground services from Before You Dig Australia (BYDA) help avoid strikes. The site needs secure fencing and signs with contact details. Use a demolition contractor who holds the licences and insurance needed for the job, and ask for copies.
Handing over a clean site
Before the new home can be set out, the builder and certifier will want:
- the asbestos clearance certificate
- proof that demolition waste went to a lawful facility
- confirmation that services are capped and old footings and pipes are removed
- a site free of debris, with any pool area filled and compacted
Ask for proof of lawful waste disposal before you pay the demolition contractor. Getting these papers together early avoids a gap between demolition and the first inspection of the new build.
For the full sequence of approvals, see our knockdown rebuild service, or request a quote for your project.
Local help across NSW
CertifiBuild certifies Class 1 and Class 10 work in 39 council areas. Local rules on these council pages are a good place to start: Penrith City Council, Canterbury-Bankstown Council, Blacktown City Council, City of Ryde, Strathfield Council, Sutherland Shire Council.
Suburb pages with local planning notes: North St Marys, Padstow, Riverstone, Ryde, Strathfield South, Sylvania, Taren Point, Warilla, Warrimoo, Watsons Bay. You can also browse every service area.
Sources
- Demolition of buildings under the exempt and complying codes, NSW Planning
- Asbestos hazards, SafeWork NSW
- Asbestos removal licences (Class B), SafeWork NSW
- MyHome Planner, knockdown rebuild demolition stage, NSW Planning Portal