A knockdown rebuild is two projects sharing a block. There is a demolition project, governed by your local government and three utilities, and there is a building project. Budgets go wrong because the first one gets treated as a line item in the second.
Most pages on this subject give you one demolition number and stop. This one sets out the statutory fees you will actually pay, with the source and the amount for each, the approvals and how long the law gives each authority to decide them, what actually moves a demolition quote, and the two costs that appear on nobody’s quote.
House & Land Co is an independent building advisory in Perth. We are not a builder, we are fee-free to you, and we are paid by our builder panel — so we have no reason to make the number look small.
What the approvals and disconnections actually cost
These are published figures, not estimates. All were read on 8 September 2026 and all are current for the 2026-27 financial year.
| Item | Amount | Source |
|---|---|---|
| Demolition permit, Class 1 or Class 10 building | $121.00 | Building and Energy, Building Act fees |
| Building Services Levy on the demolition permit | $61.65 where work is valued at $45,000 or less, otherwise 0.137% | Building and Energy |
| Water service disconnection | $1,332.92 | Water Corporation, water supply service fees |
| Electricity supply abolishment, via your retailer | $581.39 incl GST | Synergy, demolition |
| Permanent gas disconnection, where connected | $1,243.64 incl GST | ATCO, meter removal and disconnections |
| Building permit, certified, Class 1 or 10 | 0.19% of the value of the work, minimum $121.00 | Building and Energy |
| Verge bond, refundable | Set by your council — $2,369.00 at the City of Bayswater, $1,000 to $4,000 at the City of Stirling depending on street tree size | Bayswater fees and charges |
Add the fixed lines together and you are at roughly $3,340 before anyone touches the house, plus the building permit fee and levy on the new home — on a $450,000 build, about another $1,470 — and a refundable verge bond on top. Call it $4,800 in approvals and disconnections, none of which appears in a builder’s advertised price.
The verge bond comes back if the kerb, footpath and street tree survive. The fees do not come back at all.
The costs nobody quotes
Rent and loan interest
You cannot live in the house while it is being built. That means twelve to eighteen months of rent somewhere else at the same time as you pay interest on the drawn portion of your construction loan. Neither is on a builder’s quote, because neither is the builder’s to charge.
Take your likely monthly rent for a comparable home in your suburb, multiply by eighteen, and put it at the top of the budget before anything else. For most households this is the second largest number in the project. We do not publish an interest figure here because rates move; ask your broker to model the drawdown schedule against a current rate.
What demolition and the build cost
No government publishes either figure, and the ranges quoted on builder websites average jobs that have nothing in common with yours. What we can tell you is what a contractor is actually pricing.
Demolition is priced on the house and the block, not the floor area:
- Storeys. A double storey costs more than a single storey of the same footprint. The work goes up as well as across, and it is slower.
- Construction type. Brick and tile is heavier and slower to separate than weatherboard and iron, and there is more of it to cart away.
- Access. A narrow verge, a tight driveway or a power line across the frontage decides whether the crew brings standard machinery or works around it.
- Tipping and separation. Charged by weight and by material stream, so a house of clean recoverable brick prices differently to one with mixed waste.
- What is under the slab. A septic system, a filled-in pool or rubble fill is found on the day and priced then.
- Asbestos. In a pre-1990 home the survey and the licensed removal are a separate job, priced on quantity, type and location. See below.
The build side works the same way. An advertised home design price is the house, not the project: site works priced from your soil classification, retaining where the block falls, and the driveway crossover all sit outside it.
So ask for quotes in a form you can compare. Insist on separate lines for demolition, asbestos survey, licensed removal, disconnections, tipping and site clearing, and for each one ask whether it is a fixed price or a provisional sum. Ask what the quote assumes about site access and about what is under the slab, and what happens to the price if either assumption is wrong. Two quotes that include different things are not two quotes.
The fee stack above is the part that is already fixed and knowable. For the rest, House & Land Co can put you in front of our builder panel and have your own block quoted properly, at no cost to you.
We break the demolition half down line by line, including the council-by-council fees, in what demolition costs in Perth.
Why the totals online disagree
Two of the best-read Perth pages on this topic both say twelve to eighteen months. One means demolition through to handover; the other means from slab down, excluding planning and demolition. Those are different projects. Before comparing figures, establish what each one starts and stops counting.
The approvals, and how long the law allows
The demolition permit
Section 10 of the Building Act 2011 makes it an offence to carry out demolition work without a demolition permit in effect. The application is form BA5, lodged with your local government as permit authority.
The decision period is set by regulation 20 of the Building Regulations 2012: 10 business days for a demolition permit, or longer only where you agree to it in writing. There is no certified or uncertified pathway for demolition — that distinction applies only to building permits. If the permit authority does not decide in time, the application is taken to have been refused and the fee is refundable as a debt due to you.
Alongside the form, councils generally want notification to the electricity, gas, telephone and water providers, evidence of rodent treatment, consent for any work affecting neighbouring land, and the contractor’s details where asbestos is present. The City of Wanneroo, for instance, requires rodent baiting at least seven days before demolition and charges a $500 infringement for a late notice of completion.
The building permit
The permit for the new home is a separate application with its own clock, also under regulation 20:
| Application | Decision period | Fee |
|---|---|---|
| Certified, form BA1 | 10 business days | 0.19% of the value of the work, minimum $121.00 |
| Uncertified, form BA2, Class 1a and Class 10 only | 25 business days | 0.32% of the value of the work, minimum $121.00 |
A certified application arrives with a certificate of design compliance from an independent building surveyor, which is why it is decided faster. Most volume builders lodge certified as a matter of course. An informal request for more information does not stop the clock; a formal written request does, and the remaining days resume when you answer it.
Planning approval, when it also applies
A single house that meets the deemed-to-comply provisions of the Residential Design Codes can often proceed on a building permit alone. Planning approval is more likely if your block sits in a heritage or character area, if the design varies the setbacks or open space requirements, or if you are subdividing. This is the step that adds months rather than weeks.
Note that the R-Codes are no longer State Planning Policy 7.3. Since April 2024 they are a Planning Code made under Part 3A of the Planning and Development Act 2005, published by the Western Australian Planning Commission — the current edition is Residential Design Codes Volume 1, Version 3, 10 April 2026. A good deal of published advice still cites the old policy number.
Disconnecting the services
This is where demolitions get delayed, because it runs on the utilities’ timetables rather than yours.
Water. The Water Corporation charges $1,332.92 to disconnect a water or fire service, and publishes no lead time, so start early. Reconnecting later costs the full price of a new service plus a $221.22 activation fee — a 20mm domestic connection is currently $1,876.92 — so on a quick rebuild it is worth asking whether the meter should stay. Sewer is separate: a licensed plumber must disconnect the building from the sewer main and leave the connection sealed, at your cost.
Electricity. Western Power does not take this application. Their own guidance is to contact your retailer for a supply abolishment. For most Perth homes that is Synergy, which charges $581.39 including GST and asks for up to five business days. Demolition cannot start until Western Power issues a Disconnected for Demolition Notice.
Gas. Where gas is connected, ATCO charges $1,243.64 including GST, prepaid, processes the application within about three business days and completes the work generally within twenty business days. Their terms are explicit that demolition must not begin until they confirm the disconnection has been performed.
Twenty business days is a month. Lodge the gas application first.
Asbestos
If your home was built before 1990, assume asbestos until a survey says otherwise. WorkSafe WA notes that asbestos was used especially in homes built before 1990, and that the national ban on manufacture, import and use took effect on 31 December 2003.
What the rules require
Under the Work Health and Safety (General) Regulations 2022, removing more than 10 square metres of non-friable asbestos requires a Class B licence, and friable asbestos requires a Class A licence in any quantity. WorkSafe WA advises that a homeowner may remove up to 10 square metres of non-friable asbestos themselves. In practice, once you engage any contractor the site is a workplace and the licensing rules apply, so on a knockdown rebuild this is a licensed job.
A clearance is required for all licensed Class A and Class B removal work, and for residential premises the removalist is responsible for organising it. See WorkSafe WA on asbestos and the law and asbestos licences.
One point often stated incorrectly: the regulation requiring asbestos to be removed before demolition expressly does not apply to residential premises. What does apply to a house is the requirement for a competent person to inspect for asbestos before demolition and inform the owner. Your council’s own checklist is the binding constraint here, and most metropolitan councils want the asbestos position resolved before they act on the permit.
Who pays
You do. Asbestos is the owner’s cost and it is the most common reason a demolition allowance turns out short. Get the survey done before you sign anything containing an allowance.
What the block does to the price
Site classification
Before the slab is designed, an engineer classifies the soil under Australian Standard AS 2870. The class drives the footing design and therefore the cost.
| Class | What it means |
|---|---|
| A | Most sand and rock sites, little or no ground movement from moisture changes |
| S | Slightly reactive clay, slight ground movement |
| M | Moderately reactive clay or silt, moderate ground movement |
| H1 | Highly reactive clay, high ground movement |
| H2 | Highly reactive clay, very high ground movement |
| E | Extremely reactive, extreme ground movement |
| P | Problem sites: soft or loose soils, landslip, mine subsidence, collapsing soils, erosion, abnormal moisture conditions, or sites that cannot otherwise be classified |
Filled sites are classified A to P depending on what is under them. Classes M, H1, H2 and E carry a -D suffix where movement is deep-seated. Definitions are from AS 2870, as reproduced in the National Construction Code and by CSIRO.
Your block’s classification is not necessarily your neighbour’s, particularly in older suburbs where fill was brought in inconsistently. Insist the soil test is done on your land, after demolition where possible, and that the site works figure is priced from it.
Slope, access and what is under the slab
Fall across the block drives cut and fill and retaining, and narrow street access decides whether the crew can use standard machinery. What sits under the old slab — a septic system, a filled-in pool, rubble fill, a service in an unexpected place — is found only once the house is gone, which is exactly why site works is so often a provisional sum. The City of Bayswater requires septic tanks and leach drains to be removed before demolition begins.
The realistic timeline
| Stage | Duration |
|---|---|
| Design, quotes, finance and contract | 2–4 months |
| Gas disconnection | Up to 20 business days after processing — start first |
| Electricity abolishment | Allow 5 business days plus the Disconnected for Demolition Notice |
| Water disconnection | No published lead time; start early |
| Demolition permit | 10 business days statutory, plus the council’s queue |
| Asbestos removal and demolition | Demolition itself takes days; the process around it takes weeks |
| Building permit | 10 business days certified, 25 uncertified |
| Construction | Set by your building contract — get the construction period stated in writing before you sign |
Plan for around eighteen months end to end. The stages that slip are almost never the construction — they are the disconnections and approvals at the front, where most people start too late.
Your contract protections, and their limits
The Home Building Contracts Act 1991 applies to fixed-price residential building contracts between $7,500 and $500,000. Within that band a builder may take a deposit of no more than 6.5% of the contract price, and must hold home indemnity insurance and give you the certificate before starting work or demanding any payment where the work is valued over $20,000.
Two limits matter on a knockdown rebuild. Above $500,000 the Act does not apply and there is no deposit cap, and a good number of Perth rebuilds now exceed that figure. And demolition sits outside the Act entirely — the word does not appear in it — so a standalone demolition contract carries no deposit cap and no home indemnity insurance. We set out what to check in how to check a knockdown rebuild builder. Source: Building and Energy, read 8 September 2026; a review of these thresholds was due to report in September 2026.
When a knockdown rebuild is the wrong call
We say this to clients regularly and it costs us work, which is rather the point of being independent.
It tends not to stack up when the land is a small share of the total value, when the house is structurally sound and the problem is layout rather than condition, or where heritage controls will constrain the design you actually want. If that sounds like your block, read our comparison of knock down rebuild versus renovation first.
Frequently asked questions
What is the average cost of a knockdown rebuild in Perth?
There is no useful average, because the site is the variable. Budget the stack rather than the build: demolition and asbestos, plus roughly $3,340 in fixed disconnection and permit fees, plus the building permit fee and levy, plus site works, plus the house, plus twelve to eighteen months of rent and loan interest. Price each line against your own block.
Is a knockdown rebuild worth it?
It is worth it when the location carries the value and the house does not — when you would happily buy the block again today but would not buy the house. The honest test is whether you would pay today’s land value for the block with nothing on it.
Is $400,000 enough to build a house in Perth?
Whatever the answer is for the house, it is the wrong question for a knockdown rebuild, because a build price is not a project price. It leaves out demolition, asbestos, the roughly $3,340 of fees and disconnections set out above, the building permit fee and levy, site works priced from your soil classification, and your rent and loan interest for the duration. Ask a builder what their price includes and what it assumes about your block, then add the stack around it. We will do that with you at no cost.
Do I pay stamp duty on a knockdown rebuild?
No. You already own the land, so there is no transfer and no stamp duty — called transfer duty in WA — on the property. That is one of the genuine financial advantages over buying an established home elsewhere. Confirm your own position with your conveyancer.
How long does the whole thing take?
Plan for about eighteen months from first quote to handover. The approvals have statutory clocks of 10 to 25 business days, but the disconnections ahead of them set the real pace.
Where to start
Get the asbestos survey and the soil test done early, lodge the gas disconnection first because it is the slowest, and have your quotes priced against your actual block rather than a standard allowance.
If you want a second read on quotes you already hold, or an honest answer about whether your block suits a rebuild at all, our team will work through it with you at no cost. Talk to House & Land Co, or see how we manage a knock down and rebuild from approvals to handover.
