Demolishing a terrace is not like clearing a detached house on a wide block. The building is joined to its neighbours, the street is narrow, and the property is often in a heritage conservation area. Here is how the job works, from approval to an empty block, and what to expect along the way.

First question: what can be approved?

In NSW, demolition is either Complying Development, approved with a Complying Development Certificate from council or a registered certifier under the Exempt and Complying Development Codes SEPP, or it needs a Development Application to council.

Many Sydney terraces sit within heritage conservation areas, especially in the Inner West, Paddington, Surry Hills, Glebe and parts of North Sydney. Heritage items and many homes in conservation areas usually need a DA. Councils in these areas often expect the front of a terrace to be kept, with demolition limited to the rear wing and later additions. A full demolition of a contributory terrace can be hard to get approved.

So the first step is to check the planning controls for your property with council or a town planner. The answer decides everything else: what comes down, what stays, and what conditions apply.

The party wall

A terrace shares one or both side walls with its neighbours. These party walls are usually built on the boundary, and in most cases they are part of both houses. When one terrace is demolished, the party wall is normally kept, because removing it would leave the neighbour without a wall.

That changes how the work is done:

Engineering advice comes first. A structural engineer looks at the wall and specifies how it will be supported during and after demolition. That may include temporary propping, bracing at floor and roof levels, or new ties.
Demolition near the wall is done by hand. Machines work away from the shared wall, and the parts closest to it are taken apart carefully so the wall is not knocked or loaded.
Roof and floor connections are cut, not pulled. Joists and rafters that sit in pockets in the party wall are cut loose so the wall is not levered as they come out.
The exposed face is weatherproofed. Once our side is gone, the wall face that used to be inside is now outside. It is sealed and protected from weather until the new building goes up against it.

Neighbours and dilapidation reports

On a terrace job the neighbours are not just close, they are attached. Before any work starts, a dilapidation report is prepared for each neighbouring property. It records the condition of walls, ceilings, cornices, floors and finishes, with photos and notes. If a crack appears or a question is raised later, there is a clear record of what was there before.

Good communication matters as much as the report. Neighbours should know when work will start, which days will be noisy, how dust will be controlled, and who to speak to on site. A short letter before the start date, and a heads up before the loudest stages, avoids most problems.

Hazardous materials

Terraces were built long before asbestos, but most have been changed since. Rear lean-to kitchens, bathrooms and laundries added in the twentieth century often have fibro sheeting. Older vinyl floors can have asbestos backing, and some flues and fireplaces contain it too. Lead paint is also common on joinery and walls in older terraces.

A hazardous materials survey before demolition identifies what is there. In NSW, removing more than 10 square metres of non-friable asbestos needs a SafeWork NSW licensed removalist, and friable asbestos always needs a Class A licence. SafeWork NSW is notified in advance, and after removal a clearance certificate is issued before demolition continues.

Services

Before the structure is touched, services are disconnected. Electricity is handled through Ausgrid in the inner suburbs, water and sewer through Sydney Water, gas through Jemena, and telecommunications through the provider. In terraces, services often run through shared walls or roof spaces, so it is important to confirm the neighbour's supply is not affected.

Access: front door or back lane

Most terraces have no side access at all. Everything goes out through the front door or through a rear lane. That shapes the whole job:

Rear lanes are often the main route for plant and trucks. They are narrow and shared with garages and bins, so truck size and timing need planning.
Front access may mean carrying material through the house to the street, or a small machine working from the footpath with council approval.
Kerbside rules apply to skips, work zones and hoardings on council land. A permit is usually needed, and it is worth applying early.

Where the street is busy, a traffic and pedestrian management plan sets truck timing, spotters and footpath protection.

The order of work

A typical terrace demolition runs in this sequence:

Approval confirmed and conditions reviewed
Hazardous materials survey and dilapidation reports
Services disconnected
Asbestos removed and cleared
Soft strip of fittings, joinery and linings
Roof removed, working back from the party walls
Upper floor and walls removed in stages
Ground floor and rear wing removed
Footings broken out where the approval allows
Party walls weatherproofed and the site secured

What to send for a quote

To quote a terrace demolition, we need the address, photos of the front and rear, photos of the lane or street access, and any DA, CDC or plans you have. If you know whether the house is in a heritage conservation area, mention it. From there we can look at the party walls, the access and the approval conditions, and set out the order of work.

Demolishing a Terrace in Sydney: Party Walls, Neighbours and Approvals