Load Bearing Wall Removal in Perth: Beam Design and Engineering

Load bearing wall removal in Perth nearly always starts with a brick house. WA is the only state where more than half of detached houses are brick, at 68 per cent, and in a double-brick home the inner leaf of the external walls and some internal walls usually carry the ceiling, the roof or an upper floor. So the wall between your kitchen and lounge may well be holding something up. Find out before anyone picks up a hammer.

Kings Park Structural Co is advertising, not an engineering firm. We pass your enquiry to the independent structural engineering firm that advertises here, and it quotes you and contracts with you directly. The engineer who takes your job works out what the wall carries, sizes the beam and its supports, and provides the drawing and certificate your building surveyor needs. A registered builder does the building work.

There are clues you can check yourself, and they're worth knowing before you ring anyone. None of them is proof either way, and none of them tells you a wall is safe to remove.

• It's double brick. In a full-masonry house some internal walls typically carry ceilings and roof, not just the external walls.
• Something in the roof space lands on it: a strut, a prop or a beam sitting on or just above the wall.
• There's a wall or a floor directly above it on a second storey.
• Cornice cracks, sagging ceiling lines or sticking doors near the wall. These can point to movement, and that's a job for a structural inspection before any removal plan.

The rules take the guessing out of the permit question. Under WA's Building Regulations, renovation work is only exempt from a building permit if it doesn't remove or alter an element that helps support another element. A load-bearing wall is exactly that, so its removal needs a permit and engineering behind it.

A good quote comes from good information. Most engineers start with photos and whatever plans you have, then decide whether they need to see the house in person.

• Photos of both faces of the wall, the ceiling line along it and the rooms either side.
• Photos from the roof space above the wall, showing any struts, props or beams sitting on or near it.
• The house plans if you have them. Your council may hold a copy of the original approved drawings.
• Rough measurements: wall length, ceiling height, and how wide you want the opening.
• What's above: single storey, an upper floor, or a tiled or Colorbond roof.

If you're also adding floor area, the job becomes an extension and the engineering grows with it; see extension engineering. Engineers cover Greater Perth, the Perth Hills and Peel, from Joondalup and Wanneroo down to Mandurah. Call (08) 5550 6237 now to get the photos in front of one.

The engineer's output is paperwork, not a new opening. Expect a beam specification or drawing showing the beam size and grade, the posts or piers, any pad footings and the fixings, plus a signed certificate. Under the Building Act, a certified permit application must include each technical certificate the building surveyor relied on, and the engineer's certificate can be one of them.

You then choose a permit route. A certified application (BA1) goes in with a certificate of design compliance from a registered private building surveyor, and the permit authority has 10 business days to decide. An uncertified application (BA2) lets the council's own surveyors assess it, with 25 business days to decide. Both clocks stop if the council asks for more information.

A registered builder does the demolition, propping and beam installation. Residential building work over $20,000 must be covered by home indemnity insurance, and that's the builder's job to arrange. From 1 July 2027, structural engineering in WA must be done by a registered building engineer, and you can check anyone's registration on the DEMIRS Building Engineer Register.

No Perth engineering firm publishes a fixed fee for beam design. Engineers quote each job, and the price depends on the house, the span, what sits on the wall and what the council wants to see. Send photos and you'll get a written quote from the engineer before any work starts.

The government charges are published, and they're calculated on the estimated value of the work including GST:

• Certified building permit: 0.19% of the value, minimum $121.00.
• Uncertified building permit: 0.32% of the value, minimum $121.00.
• Building Services Levy: $61.65 if the work is $45,000 or less, or 0.137% above that.
• Construction Training Fund levy: 0.2%, but only where the work is worth more than $100,000.

On a $30,000 kitchen-and-wall job, 0.19% comes to $57, so the $121.00 minimum applies, plus the $61.65 levy. The builder's price for the beam, propping and making good is separate. Our structural engineer cost guide covers the rest.