Cost to Build a House in Perth

What it actually costs to build a house in Perth

There is no honest single answer to this question. Any builder who gives you one before seeing your block is guessing. The cost to build a house in Perth is driven by four things: the land you are building on, how big the house is, how complicated it is to build, and the level of finish you choose.

Two homes of identical floor area, on two blocks a street apart, can differ by hundreds of thousands of dollars. Site works, retaining and specification account for most of that gap.

What we can do is explain how the number is built up. That way you can read a quote properly, and work out where your own project is likely to land. If you would rather skip to a figure for your specific block, get in touch and we will work through it with you.

1. The block and site works

This is the biggest source of surprise in most budgets. In fact, it is the largest single variable in the cost to build a house in Perth.

Slope, retaining, sand pads and fill, rock, groundwater, tree removal and demolition all add cost. So do service connections and difficult access. All of it lands before a single wall goes up.

By contrast, a flat, cleared, serviced lot with easy street access is the cheapest starting point you can have.

2. Size, storeys and footprint

Floor area matters. However, shape matters nearly as much.

A second storey brings structural, stair, access and scaffolding costs. A single-storey home of the same area avoids all of them.

Complex rooflines, long wall runs and lots of corners all cost more. A simple, efficient footprint encloses the same space for less.

3. Specification and finishes

Kitchens, joinery, stone, tiling, tapware, glazing, flooring, doors and hardware cover an enormous range of prices.

Fortunately, this is the part of the budget you control most directly. It is also where the gap between a mid-range and a high-end build mostly lives.

4. Design complexity

Cantilevers, large spans, extensive glazing, voids and suspended slabs all require more engineering and more skilled trade time. So do integrated pools and non-standard materials.

They can be worth it. Even so, they should be costed while the design is still on paper.

What per-square-metre figures do and do not tell you

Cost guides published for the Perth market in 2026 commonly quote construction-only rates in the range of roughly $2,000 to $2,700 per square metre for mid-range work, rising to around $2,700 to $4,200 per square metre for high-end custom homes and higher again for genuinely luxury specifications. Those figures are a useful sanity check on the cost to build a house in Perth, and nothing more.

Firstly, it usually refers to the building only. As a result, site works, retaining, driveways, landscaping, fencing, window treatments and authority fees all sit outside it. It also flattens a real difference. A simple rectangular single-storey home is not the same build as a two-storey design with a suspended slab and eight metres of stacking glass. Therefore, use it to sense-check a quote rather than to set your budget.

A more reliable approach is to start with your total available budget. Then subtract everything genuinely outside the build contract, and design to what is left. Above all, that order avoids a common and painful experience: falling in love with a design you cannot build.

Costs people forget to budget for

Site works and retaining

These are rarely fixed until a contour survey and geotechnical report exist. On a sloping or filled block this line alone can run well into five figures.

Approvals and authority fees

Development approval where required, the building permit and the Building Services Levy administered by Building and Energy, the Construction Training Fund levy on higher-value work — note the CTF threshold rises from $20,000 to $100,000 from 1 July 2026 — plus water and power connections and any shire-specific charges.

Landscaping and external works

Driveways, paths, fencing, retaining outside the building footprint, reticulation, lawn and planting are usually excluded from a build contract and often total more than people expect.

The finishing layer

Window treatments, security screens, letterbox, clothesline, TV and data cabling, appliances beyond the standard package, and furniture. Individually small, collectively significant.

Questions we get asked most about the cost to build a house in Perth

Can you build a house for $300,000 in Perth?

You can build a modest project home in that range on a straightforward block, and volume builders in Perth advertise packages around that mark. A custom home is a different proposition: once you add site works, a bespoke design and any real specification, that figure becomes difficult. If $300,000 is your total build budget, a project builder is usually the more sensible route and we will tell you that honestly rather than take you through a design process that cannot land.

Is $400,000 enough to build a custom home?

It can be, depending on size, block and finish level. At that budget the design has to be disciplined — an efficient single-storey footprint, a simple roof form, restrained glazing and a considered rather than extravagant specification. What it will not stretch to is a large two-storey home with a high-end finish, and it is better to know that at the first meeting.

How much does a two-storey four-bedroom home cost in Perth?

Two-storey construction carries a premium over single-storey for the same floor area because of structure, stairs, scaffolding and access. A four-bedroom two-storey custom home sits well above entry-level project pricing, and the final figure depends heavily on the block, the extent of glazing and the finish level. We would rather give you a range against your actual site than quote a number that turns out to be meaningless.

Is it cheaper to build or to buy in Perth?

It depends on the suburb. In established areas where existing stock is old and land values are high, building can deliver a far better home for a comparable total outlay. In newer estates, buying an existing home can be cheaper than replacing it. The honest comparison is total cost against what you actually end up living in, not build cost against purchase price.

Contracts, contingency and knockdown rebuilds

Do you offer fixed-price contracts?

We put the scope and inclusions in writing before contracts are signed so you can see exactly what is covered. The parts of a build that genuinely cannot be fixed until more is known — typically site conditions on an unsurveyed block, or what is found once an existing structure is opened up — are identified as such rather than buried in the fine print.

What is a realistic contingency to hold?

Holding a contingency is sensible on any build and essential on a difficult site or a renovation. Clients who set aside a genuine buffer tend to enjoy the process considerably more than those who commit every last dollar to the contract sum and then face a decision about a variation.

How much does a knockdown and rebuild cost compared with building on vacant land?

Demolition of a standard single-storey brick and tile home is usually a five-figure job on its own, and it is only the start. Service disconnections, asbestos assessment and removal where the home predates the mid-1980s, site clean-up, and the fact that established suburbs often have tighter access all add cost that a vacant lot does not carry. Against that, you are usually building in a suburb where land is scarce and values are high, which is exactly why so many Perth projects still stack up as a knockdown and rebuild.

Does a two-storey home cost more per square metre than a single-storey?

Generally yes. A second storey adds structural work, a suspended floor, stairs, scaffolding, additional inspections and a longer trade sequence, and those costs do not scale down with area. What a two-storey design buys you is more house on less land, which on a narrow or expensive block often makes it the more economical route overall even at a higher rate per square metre.

Next steps

The most useful thing you can do is get a realistic figure for the cost to build a house in Perth on your own block, rather than a general one. We look at your site, your brief and your budget together and tell you what is achievable — including when the answer is that a different approach would serve you better.

Read about how our building process works, see completed projects, or learn how long a custom build takes in Perth. We build custom homes across the Perth metro area.