Knocking out a wall, adding a room or staring at a new crack south of the river? Call and we'll pass your job to an independent structural engineer who quotes you directly.
Cockburn, Melville and Canning cover a big slice of the southern suburbs: the ABS counted 139,499 people in Cockburn, 115,945 in Melville and 109,028 in Canning in mid-2025. The calls from here tend to be everyday ones: a wall coming out for an open-plan kitchen, a crack that wasn't there last summer, an extension the building surveyor wants engineered, or a patio that needs a certificate before the permit is issued.
Kings Park Structural Co is a referral service, not an engineering firm. We pass your enquiry to an independent structural engineering firm, which pays us for the introduction and quotes and contracts with you directly. Sometimes the honest first answer is that you don't need an engineer at all, and we'd rather you knew that before you spend money.
WA is the only state where more than half of detached houses are brick, and in a double-brick house internal walls often carry the ceiling and roof. An independent engineer checks the wall and designs the beam before a builder in Cockburn, Melville or Canning touches it.
For owners worried about cracks in brickwork, render or ceilings, or who need an independent report for a purchase, a builder dispute or an insurer. It's an engineer's assessment, which is a different thing from a pre-purchase building inspection.
Any change to floor area or height needs a building permit, and the building surveyor will want engineering for footings, beams and any new load on existing walls. The engineer quotes once they've seen your plans.
A roofed patio isn't a pergola under the WA exemptions, so most patios and carports need a permit. An engineer's certificate covers the design, the wind loading and the footings for your particular block.
Your building permit comes from the City of Cockburn, the City of Melville or the City of Canning, depending on where you live. The rules underneath are the same across WA: the Building Regulations 2012 say that removing a load-bearing wall, changing floor area or height, or replacing footings is not exempt work, so it needs a permit.
You can apply two ways. A certified application (BA1) comes with a certificate of design compliance from a private building surveyor, and the council has 10 business days to decide. An uncertified application (BA2) goes to the council's own surveyors and has 25 business days. Either way the clock stops if the council asks for more information, so engineering that answers the surveyor's questions first time can save you weeks.
Permit fees are set by regulation: 0.19% of the estimated value of the work for a certified permit, or 0.32% for an uncertified one, with a minimum of $121.00. The value is counted including GST. Our cost guide has the state levies that sit on top.
Sand is the most common soil in metropolitan Perth, and a sand site is normally Class A under AS 2870, with little movement between wet and dry seasons. Geoscience Australia maps Bassendean Sand across much of central Perth, with Spearwood sand and Tamala Limestone along the coastal strip. Nobody has published which soil sits under which southern suburb, so the engineer judges your block when they see it.
Sand doesn't shrink and swell like clay, but CSIRO says it is particularly easy to wash away. A leaking pipe, a downpipe that dumps roof water beside the footings, or reticulation left on too long can all undermine a footing. In brickwork that tends to show as step cracks in the mortar or vertical cracks at doors and windows.
CSIRO grades cracks by width, from under 0.1 mm (negligible) up to 15 to 25 mm (severe). A tape measure tells you which band a crack is in, but not what caused it or whether it's still moving. That's what a structural inspection is for.
Some small jobs are exempt from a building permit. A pergola is exempt if it has no roof, is no more than 2.4 m high, covers 20 m2 or less and isn't in wind region C or D. A freestanding shed can be exempt up to 10 m2 and 2.4 m high, on the same wind condition. A roofed patio doesn't count as a pergola, so it usually needs a permit and, with it, engineering.
If your job falls outside those limits, have photos, any existing plans and a rough sketch ready when you call. See patio and shed certificates, wall removal engineering or extension engineering for what each job involves.
From 1 July 2027, structural engineering work in WA must be done by a registered building engineer. You can look up any engineer on the DEMIRS Building Engineer Register before you sign anything, and it's worth the two minutes.
Unauthorised work is regularised with a building approval certificate, and the City of Canning uses form BA13 for unauthorised Class 1 or Class 10 work. The state fee is 0.38% of the estimated value, minimum $121.00. The process Perth firms describe includes a building surveyor's certificate and an engineer's inspection and certification of what was built, which the engineer quotes after seeing photos or the site.
The regulations give the council 10 business days for a certified application and 25 business days for an uncertified one, unless you agree in writing to longer. The clock stops if the council asks for more information. Engineering has to be done before you lodge, so ask the engineer for their turnaround when they quote.
Perth engineering firms generally don't publish prices, and we won't guess one for you. Engineers quote each job, and the price depends on the house, the structure and what the council needs. Government charges are fixed, though: a certified permit is 0.19% of the value of the work with a $121.00 minimum. Our cost page has the rest.
Yes. Enquiries from anywhere in the three council areas go to an independent engineering firm, which quotes you directly. If you're nearer Rockingham or the coast, see our Rockingham and Kwinana or Western Suburbs and Fremantle pages. Otherwise call (08) 5550 6237.
Tell us what you need looked at and get a written quote.
