Knockdown rebuild certification

What does fast-track demolition need?

Demolition can be approved under a CDC (a fast-track approval from a certifier) when it complies with the state demolition rules. The job has to follow AS 2601, the demolition standard. Services must be disconnected as each provider requires. Erosion and sediment controls must keep soil and debris on the lot.

You must notify your neighbours before demolition starts. Contact each service provider early, as some disconnections must be booked and demolition cannot start until they are done.

In a heritage conservation area, or a proposed one, fast-track demolition is very limited. Demolishing the house itself usually needs a development application to council. The same applies where a heritage item sits on the lot. Check the planning certificate and heritage maps before your builder prices the job.

Who can remove asbestos?

Friable asbestos crumbles to powder in your hand when dry. Removing any amount needs a Class A licence. Bonded (non-friable) asbestos over 10 m² can only be removed under a Class B licence or higher. SafeWork NSW recommends a licensed professional even for smaller amounts.

Licensed removalists must notify SafeWork NSW 5 calendar days before work starts. A clearance inspection is done before anyone goes back in. A business removing 10 m² or less without a licence must still follow the code of practice and train its workers. After friable removal, an independent licensed asbestos assessor issues the clearance. After bonded removal, a competent person or assessor can, but they must not be linked to the removal business.

Asbestos conditions on your certificate

Your certificate will carry extra conditions if the work involves any friable asbestos, or bonded asbestos over 10 m². The certifier must get a signed contract showing a licensed removalist will do the work. It must name a landfill site licensed to take asbestos. The landfill must then give a receipt confirming it got the asbestos. An owner-builder cannot remove this asbestos themselves.

Telling SafeWork about demolition

Some demolition also needs notice to SafeWork NSW at least 5 calendar days before. This applies when demolishing a load-bearing part of a structure at least 6 m high, using heavy machinery on a suspended floor, or using explosives. A two storey house can reach 6 m, so ask your demolition contractor early. SafeWork sends an acknowledgement, not an approval, and work cannot start until the 5 days have passed.

Sydney Water before the old house goes

In Sydney Water's area, excavating, demolishing or building on a property needs a building plan approval. It confirms the work will not damage Sydney Water pipes or stop crews reaching them for repairs. Applications are lodged online using Sydney Water's Tap in service, and where work is close to or over a pipe, you are referred to a water servicing coordinator for a detailed assessment.

Disconnecting the old house from drinking water or wastewater services is a separate Tap in application. Approval comes as a letter setting out conditions for the disconnection, which your plumber then follows.

Order the sewer service diagram early in design. A new home with a bigger footprint can reach a pipe that the old house cleared, and moving the house on paper is far easier than redesigning footings once the problem is found on site.

Land that rules out a combined CDC

Whether one CDC (complying development certificate) can cover both the knockdown and the new house turns on the land being eligible. Complying development is generally unavailable for land holding a State Heritage Register item or covered by an interim heritage order, and for land with Class 1 or 2 acid sulfate soils, coastal hazard land, land affected by aircraft noise at ANEF (Australian Noise Exposure Forecast) 25 or above, environmentally sensitive land, or land set aside for public purposes.

Bushfire prone and flood prone land is not excluded outright. Extra standards apply under the code's bushfire and flood clauses, and the new home must meet them in addition to the general Housing Code rules.

A CDC also does not override private covenants on the title. Covenants can control matters such as materials, fencing or how many dwellings a lot may hold, and they continue to bind you after approval, so read the title before design starts.

Trees and work on the street

An established lot often comes with mature trees. The Housing Code sets setbacks to protected trees, and council should be asked before removing or pruning any tree or vegetation. That includes trees the demolition contractor wants gone for machine access.

Anything built beyond your boundary is approved separately. Structures on public land or over a public road need consent under both the Roads Act and the Local Government Act, which can catch a new or moved driveway crossing. Ask council what applies before the site plan is finalised.

A levy paid before approval issues

NSW charges a levy for long service on building and construction work whose cost reaches $250,000, GST included, at a rate of 0.25%.

Payment is due before work begins. A council or certifier is not able to release a CDC or construction certificate while the levy is unpaid. Responsibility for paying sits with the applicant on the approval, or with whoever the work is being carried out for. Holders of a NSW Fair Trading owner-builder permit may qualify for a reduction.

Base the application on a realistic estimate for the whole job, since that cost figure drives the amount payable.

Rebuilding in a mine subsidence district

Parts of NSW lie in mine subsidence districts. Every property in one is given its own surface development guideline, limiting the type, size, height, location and materials of what can be built. The guideline for a lot can be looked up on the NSW Planning Portal's ePlanning Spatial Viewer.

Where a lot has guideline 2, 3 or 3A, or guideline 6 or 8, councils and registered certifiers are able to approve complying development that meets it. Subsidence Advisory NSW itself must approve work that does not comply, and any work on lots with guideline 1 or 1A, or guideline 4, 5 or 7. Guidelines can change over time, so check the current one before design, even though different rules may have applied when the old house went up.