Best builders in the Perth Hills: Kalamunda, Lesmurdie & Mundaring, WA (2026)
Table of Contents
These are the best-rated builders and renovation companies working the Perth Hills: Kalamunda, Lesmurdie, Forrestfield, Gooseberry Hill, Mundaring and Glen Forrest. They're ranked on real Google reviews, not on who paid us. The Hills are a genuinely small market for this trade, far fewer registered builders than the flat metro suburbs, because the population is smaller and blocks are bigger, so this is a short, honest list rather than a padded one. Building here comes with its own conditions: bushland blocks, sloping and rocky ground, longer driveways and access tracks, and for a lot of properties a bushfire attack level (BAL) rating that shapes what materials you can use and adds real cost. One thing to know up front: builders collect far fewer Google reviews than plumbers or pest controllers, because most people build or renovate once or twice in a lifetime, and that's even more true out here where there are simply fewer builders to go around. Whatever the job, get a fixed-price contract, a registered builder, home indemnity insurance sighted before any money changes hands, and ask specifically how they handle BAL requirements and hills access before you sign.
Featured builders
These spots are for Kalamunda, Mundaring and Perth Hills builders and renovators who want to stand out on this page. None are taken yet, so the full review-ranked list is right below. That ranking is earned off Google reviews and never for sale. Are you a registered builder or renovation company working Lesmurdie, Forrestfield, Gooseberry Hill or Glen Forrest? Featured spots start at $50 a year.
⭐ 91 Google reviews behind this list
📍 Kalamunda, Mundaring & the Perth Hills, WA
🔄 Updated monthly
How we ranked these builders
- Google reviews do the ranking. We start with every builder's live Google star rating and the number of reviews behind it, pulled fresh from Google Maps.
- Rating, weighted by volume. A 5.0 off one or two jobs isn't proof yet, so we weight the score by review count. OZ Home Building & Construction carries by far the deepest record in the Hills (65 reviews) at a perfect 5.0, which is why it leads the page ahead of everyone else here.
- A genuinely thin market, honestly framed. The Perth Hills have far fewer registered builders than the flat metro suburbs, smaller population, bigger blocks, more owner-builders. We only found four operators with a meaningful, genuine Google review record actually working this ground. Rather than pad the list with Perth-wide volume builders who happen to service the area on paper, we've kept it to the ones genuinely based in or working the Hills.
- Serving the Hills suburbs, honestly framed. OZ Home Building & Construction is based in Kalamunda, Cooper Builders WA in Hovea near Mundaring, and Kalamunda Carpentry in Gooseberry Hill, all three sit inside the cluster. Second Storey Solutions is based just off the escarpment in Hazelmere and regularly works Forrestfield and the Hills fringe.
- Builders, not tradies or suppliers. We only counted businesses doing the actual building or renovation project management, not individual trades or building-material suppliers.
OZ Home Building & Construction
OZ Home Building & Construction tops the page on a perfect 5.0 across 65 reviews, easily the deepest record of any builder in the Perth Hills. Based right in Kalamunda, reviewers call out a crew that finishes on time and delivers results that exceed expectations, from full bathroom transformations to larger builds.
Cooper Builders WA
A perfect 5.0 from 10 reviews and based right in Hovea, deep in the Mundaring end of the Hills. If your block has slope, bush and a long driveway, a builder who already works this ground is worth more than one quoting off a flat suburban block.
Kalamunda Carpentry
A locally based carpenter and renovation builder working out of Gooseberry Hill, sitting on a solid 4.5 from 8 reviews. Good middle ground between a full builder and a specialist tradesperson for smaller renovation and extension jobs in the Hills.
4.4
(8 reviews)
What building and renovation work actually costs in the Perth Hills (2026)
| Job | Typical cost | What moves the price |
|---|---|---|
| Bathroom renovation (full strip-out and refit) | $18,000-$40,000 | Layout changes, waterproofing, tiling area, fixtures and tapware, moving plumbing, second-storey access |
| Kitchen renovation (full) | $22,000-$60,000 | Cabinetry and stone, appliances, moving services, structural wall removal, high-end finishes |
| Room addition / rear extension (ground floor) | $2,500-$4,500 / m² | Site access, footings on sloping or rocky hills ground, matching the existing roofline and brickwork, finishes |
| Second-storey addition | $280,000-$600,000+ | Engineering, existing footings, staying in the house during the build, structural upgrades, extra glazing and engineering |
| Whole-house renovation (cosmetic to structural) | $120,000-$400,000+ | Extent of structural work, kitchen and bathrooms, re-wire and re-plumb, age and condition of the home |
| New custom home (build only, per m²) | $2,200-$4,000+ / m² | Single vs double storey, spec level, block slope and soil, bespoke design |
| Knock-down-rebuild (demolition + new home) | $450,000-$900,000+ | Demolition and site clearing, asbestos removal on older homes, home size and spec, reactive clay in the foothill suburbs |
| Granny flat / ancillary dwelling | $120,000-$260,000 | Size, kitchen and bathroom fit-out, connecting services, site access, whether it's transportable or built on site |
| Patio, alfresco or outdoor living | $8,000-$40,000 | Size, roof type, decking, flooring, whether it ties into the house structure |
| Home indemnity insurance (builder arranges, on work over $20k) | Built into contract | Contract value; legally required in WA and passed on in the build price |
Building in the Hills carries costs the flat suburbs don't. Many blocks fall in a Bushfire Prone Area, and depending on the Bushfire Attack Level (BAL) assessment, you may need BAL-rated windows, doors, decking and roofing, that can add a meaningful amount to a build or extension, so get the BAL assessment done before you price the job, not after. Sloping and rocky blocks push up site works, footings and retaining compared with a flat suburban block, and long or steep driveways can add access and haulage costs for a knock-down-rebuild or a big renovation. A lot of Hills properties are also on bore water and septic rather than mains, which a builder pricing your job needs to know about upfront. And whatever the job, the big cost driver is scope creep: every extra decided on-site after the contract is signed is a variation, and variations are what blow out an otherwise sensible budget.
Don't get ripped off: red flags
- Not a registered builder. In WA, residential building work over a set value must be carried out by a builder registered with the Building Services Board. Ask for the registration number and check it on the Building and Energy (DMIRS) register before you sign. An unregistered "builder" leaves you with no proper comeback.
- A deposit over the legal cap. Under WA's home building contract rules the deposit is capped at 6.5% of the contract price. Anyone asking for 10, 20 or 30 per cent up front is breaking the rules and putting your money at risk. Walk away.
- No home indemnity insurance. For residential work over $20,000, the builder must take out home indemnity insurance and give you the certificate before they take a deposit or start. It protects you if they die, disappear or go insolvent mid-build. No certificate, no start.
- No written contract, or a vague one. Building work over the WA threshold needs a proper written contract with a fixed scope, a fixed price or a clear pricing basis, and a schedule of progress payments. A one-page quote with "the rest TBC" is how disputes start.
- Progress payments not tied to stages. You should pay in stages against work completed, deposit, slab, plate height, lock-up, fit-out, practical completion, not big lump sums ahead of the work. Paying well ahead of the build leaves you exposed if it stalls.
- The quote is thousands cheaper than everyone else. On a build, the lowball quote is usually the most expensive in the end, either it's missing scope that comes back as variations, or the finishes are stripped down to hit the number. Compare quotes on identical scope and specification.
- Cash discounts and "start Monday" pressure. A builder pushing a cash deal, no contract, or urgency to sign today is a builder to avoid. Good builders have a waitlist and work to a contract.
- Vague on the building permit. Nearly all structural work needs a building permit from the local council or a private certifier. If a builder shrugs off permits or offers to "do it without", you wear the risk when you sell or insure.
- No allowances spelled out. Watch for "prime cost" and "provisional sum" allowances set artificially low, for tiles, tapware, flooring or site works, so the headline price looks sharp and blows out later. Ask what each allowance assumes.
- Won't give references or show finished work. A builder proud of their work will happily point you to a recent finished home or a client to ring. Reluctance is a tell.
Before you hire: quick checklist
- Registered builder. Confirm the builder or company holds current registration with the WA Building Services Board and check the number on the Building and Energy register. It's a legal requirement for residential work, not a nice-to-have.
- Written contract on the right terms. Get a proper written building contract with a fixed scope, the price or pricing basis, the progress-payment schedule and the finish allowances all spelled out before any money changes hands.
- Deposit within the cap. Check the deposit is no more than 6.5% of the contract price, the WA legal maximum. Anything higher is a warning sign.
- Home indemnity insurance certificate. For work over $20,000, sight the home indemnity insurance certificate before you pay a deposit or let work start.
- Building permit sorted. Confirm who's obtaining the building permit and that it's in place before structural work begins.
- Right builder for the job. Match the builder to the project, a volume new-home builder, a custom builder and a renovation specialist each suit different work. Ask to see a recent finished job like yours.
- Allowances and variations. Understand every prime-cost and provisional-sum allowance, and how variations are priced and approved, before you sign. This is where budgets blow out.
- Recent, specific reviews and references. Look for recent reviews that mention the actual build or reno, and ask for a client or two you can call. A steady stream beats one old burst of five stars.
Frequently asked
How did you rank these builders?
By their live Google star rating and the number of reviews behind it, pulled from Google Maps. We rank by star rating first, and break ties by review volume, which is why OZ Home Building & Construction (5.0 from 65 reviews) leads the page by a wide margin, the deepest review record of any builder working the Hills. The Perth Hills are a genuinely small market for this trade, so rather than padding the list with Perth-wide volume builders who service the area on paper, we kept it to operators genuinely based in or working Kalamunda, Mundaring and the surrounding suburbs.
Which areas does this cover?
Kalamunda, Lesmurdie, Forrestfield, Gooseberry Hill, Mundaring and Glen Forrest. Every business on this page was checked to genuinely service this stretch of the Perth Hills.
Are these paid placements?
No. This list is ordered on Google review data. Businesses can pay for a "Featured" spot at the top of the page, clearly marked as Featured, but that never changes where anyone sits in the review-based ranking below it.
Why is this list shorter than your other builder pages?
Because the Perth Hills are a genuinely smaller market. Fewer people live here than in the flat metro suburbs, blocks are bigger, and a fair amount of building work is owner-managed or done by builders based elsewhere in Perth who take on the odd Hills job. We only found four operators with a real, meaningful Google review record genuinely working this ground, so that's what we've published rather than stretching the list to look fuller than the market actually is.
Does my builder have to be registered in WA?
Yes. Residential building work over a set value in Western Australia must be carried out by a builder registered with the Building Services Board, administered by Building and Energy within DMIRS. You can check a builder's registration on the public register. Always confirm registration before you sign, and be wary of anyone who can't give you a number. This is general information, not legal advice, so check your specific job with Building and Energy WA if you're unsure.
How much deposit can a builder ask for?
Under WA's home building contract rules, the deposit on a residential building contract is capped at 6.5% of the contract price. If a builder asks for more up front, that's a warning sign. After the deposit you should pay in stages against completed work, not in large lump sums ahead of the build. Again, general information rather than legal advice, so check the current rules with Building and Energy WA.
What is home indemnity insurance and do I need it?
Home indemnity insurance protects you, the owner, if your builder dies, disappears or becomes insolvent before the work is finished or a warranty issue arises. In WA it's required for residential building work over $20,000, and the builder must arrange it and give you the certificate before taking a deposit or starting work. Don't let a build begin without sighting that certificate.
Should I get a fixed-price contract?
For most home builds and renovations, a fixed-price contract on a clearly defined scope is the safest way to keep control of your budget. The catch is variations: any change once the build starts is priced as a variation, and that's where a tidy fixed price can blow out. Lock the scope, the finishes and the allowances down in the contract before work begins, and make sure the contract sets out how variations are priced and approved.
How often is this page updated?
Monthly. Ratings and review counts move, new builders earn their spot, and we re-pull the data so the list stays honest and current. As Perth Hills builders build up reviews, expect this list to shift.
Are you a builder in Kalamunda, Mundaring or the Perth Hills?
Get in front of homeowners who are ready to build or renovate. Claim your free listing, or ask about a Featured spot on this page.
Last updated: July 2026