Planning a knockdown rebuild in Perth? Learn what to prepare before contacting a builder, from budgets and permits to design choices and site assessments.
For many Perth families, the best block they will ever find is the one they already live on. The street is familiar, the schools are close and the trees are fully grown. What no longer fits is the house. That is why a knockdown and rebuild has become a common path in established suburbs, from the western suburbs to the river and the northern coast.
Pulling down a house and building a new one is a bigger undertaking than buying a vacant lot. The good news is that most of the surprises can be found early, before anything is signed. These are the things worth sorting out first.
1. Check the block before you set the budget
Every block comes with rules, and they decide what you can build long before a designer starts drawing. Look up your zoning and density code, and check whether the street sits in a heritage area or the house itself is listed. Easements, sewer lines, a sloping site and protected trees on the verge can all shape the footprint.
Your local council can tell you most of this, and a builder experienced in rebuilds will often check it for you at the first meeting. It is far cheaper to learn about a setback now than after the plans are finished.
2. Budget for more than the build
The build price is the biggest number, but it is not the only one. A realistic rebuild budget also covers:
demolition, which Trendsetter Homes puts at typically $15,000 to $40,000 depending on the size and access of the existing house
asbestos removal, if the house contains it
disconnecting and reconnecting power, water, gas and sewer
council application and permit fees
rent or other accommodation while you are out of the house
landscaping, fencing and driveways, which are often outside the building contract
Ask any builder to show clearly what their price includes and what it leaves out. A short list of exclusions on paper is worth more than a low headline figure.
3. Plan where you will live, and for how long
Most of the work on a rebuild happens before the old house comes down. Design, engineering and approvals can take months, and you can stay in your home for all of it. Trendsetter Homes estimates a full demolish and build project at anywhere from eight months to more than two years, depending on the design and the approvals involved.
Line up your temporary accommodation once your builder gives you a likely demolition date, and build some slack into the lease. Moving out too early is an expensive way to wait for a permit.
4. Find out what the old house is made of
Many Perth homes built before 1990 contain asbestos, often in eaves, wet-area linings, fences and older roof sheeting. In Western Australia, removing more than 10 square metres of asbestos must be done by a licensed removalist. An inspection before demolition tells you what is there and what it will cost to remove safely, so it does not become a surprise once the site is fenced off.
5. Choose a builder who manages the whole process
A rebuild has more moving parts than a standard build: demolition, service disconnections, permits, neighbours and site access. Life is much simpler when one team coordinates all of it. When you compare custom home builders in Perth, ask whether they handle the demolition and approvals themselves or leave them to you.
A few more questions are worth asking at the first meeting:
Can I walk through a home you have finished, or one under construction? Floor plans and renders only tell part of the story.
How are variations priced and approved during the build?
Who will be my day-to-day contact, and how often will we meet on site?
What is your builder registration number? You can check it on the Building and Energy register, and your builder must take out home indemnity insurance for residential work over $20,000.
Builders who specialise in this kind of work will usually have a clear process for it. Trendsetter Homes, for example, sets out its approach to a knockdown rebuild, from permits and utilities through to demolition and handover.
Start with the conversation, not the plans
A knockdown rebuild lets you keep everything you love about where you live and change everything you do not about the house. Doing the groundwork first, on the block, the budget, the timing and the builder, is what keeps the project on track once the old house comes down.
About Trendsetter Homes
Trendsetter Homes is a family-owned Perth custom home builder, founded in 1997 and led by Managing Director Michael Agostino. The company designs and builds one-off luxury homes across metropolitan Perth, including knockdown rebuilds. It won the Master Builders WA 2026 Contract Home $1 million to $2 million award for The Grosvenor and the HIA Perth 2025 Custom Built Home $1.2 million to $1.7 million award for a home in Marmion. Builder registration BC 10254.
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