Nahuel Acosta Martinez
Perth, WA
“This is a great construction company, and I trust them completely. Tom is always communicative and professional, and his experience really shows in the quality of his work. Highly recommended.”
Google Review
Home Extensions
Home Extensions in Perth, Designed Around How You Actually Live
Whether it's a single-storey addition at the back or a second-storey extension, we design and build extensions across Perth's western suburbs with transparent, disclosed pricing and no surprises on variations.
Licensed WA Builder (BC105853)
Council approvals handled for you
Based in Subiaco
Free Home extension Calculator
Home extension Cost Calculator Perth
Get an instant indicative estimate for your project. Cost of works and our disclosed management fee are shown separately, consistent with your formal quote. All prices include GST.
Estimating renovations only. Need a different project type? Try the full calculator.
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Choose Project Type
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Project Size
20
m²Storey
3
Finish Level
4
Optional Add-ons
Your Estimate
📐Home extension
Estimated Cost of Works
$51,000
$2,550 per m²
Materials, labour and subcontractors only — our management fee is shown separately below.
Low
$34,000
High
$68,000
Management fee (18.5%, locked & disclosed)$6,290 – $12,580
Estimated total project cost$40,290 – $80,580
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Estimates are indicative only. Cost of works excludes our locked, disclosed 18.5% management fee, shown separately above. Final pricing requires a formal site-specific quote from our team.
Overview
More Space, Without Changing Address
An extension is almost always cheaper than buying a new house and far less disruptive than a knockdown-rebuild, while letting you keep the street, the neighbours and the land you already know. We design each extension around your block's actual constraints — R-Codes, setbacks, existing structure — not a generic template.
As your licensed builder we handle the design, the council approvals and the construction under one roof, with every cost disclosed against a single, locked management fee agreed before work starts.
What's typically included
Single or double-storey extension design and construction
Assessment of the fastest available approval pathway for your design
Council approvals and building permits
Open-plan layout modifications and garage conversions
Structural engineering and footing assessment for second-storey additions
Full BCA-compliant construction, fully insured
Google Reviews
Real feedback from Regional Construct clients
5.0 stars across 19 Google reviews. Rotating through real client feedback below — see the full set on Google.
Read All Google ReviewsWhy We're Different
Why We Build This Way
Built to Finish What We Start
Our management fee is locked and disclosed before work starts, so we're financially committed to your build the same way on day one as on day one hundred — steady quality and pace, first brick to handover.
Full Cost Transparency
You see the real cost of your build and exactly what our fee covers, every time.
Fair, Disclosed Variations
Scope changes are billed at the real invoiced cost with the same disclosed fee added — what you see is what you pay, every time.
Flexibility
Change finishes or scope mid-build and your fee structure stays exactly the same.
FAQ
Common Questions
Ground-floor extensions typically run $2,000–$4,000 per square metre depending on scope and finish, so a 40m² single-storey addition commonly lands between $80,000 and $160,000 in construction cost. Second-storey additions usually cost around 50% more per square metre than a ground-floor extension, due to extra structural engineering, temporary propping and services runs. On top of the build cost, budget your total project 25–40% higher again to cover professional fees, council approvals and a sensible contingency. Use the estimator below for an indicative figure, or get a free, site-specific quote.
Almost all extensions need at least a building permit. Straightforward single-storey extensions that meet your council's deemed-to-comply provisions can sometimes be fast-tracked, while larger extensions, second storeys or anything affecting a heritage overlay usually need a full development application, which can take several months. We assess which pathway applies to your project and manage the approval process from there.
Most Perth homes can, but it depends on the existing footings and structure. We assess this during the initial site visit and can advise on any strengthening work required before the second storey goes ahead.
A second storey usually means strengthening the existing footings to carry the extra load, temporarily removing or propping the roof, and running plumbing and electrical services up through the existing floor — none of which apply to a straightforward ground-floor addition. That extra structural and logistical work is why second-storey extensions typically cost around 50% more per square metre.
In most cases, yes, particularly for single-storey extensions that don't touch the existing structure significantly. We sequence work to minimise disruption and will flag upfront if part of the project makes more sense with temporary alternative arrangements.
A single-storey extension typically takes 3-6 months from council approval to handover. A second-storey addition usually takes 6-12 months given the additional structural and engineering requirements.
Yes — it's free, gives an instant indicative estimate for single or double-storey extensions, and you don't need to submit any details unless you want a formal, site-specific quote.
It's a genuine indicative range based on real Perth build rates for size, storeys and finish level, not a marketing number. Your exact cost depends on your existing home, chosen finishes and site conditions, confirmed during a free assessment.
Our Promise
Our 10% Guarantee
Transparent Pricing, Backed By Our Guarantee
If your final cost tracks more than 10% above our upfront estimate, we'll automatically bring in our in-house experts for a free consultation — reviewing where costs are tracking over and identifying options to bring your build back on budget. No extra charge, and we act on it proactively, before you have to ask.
Get Started
Ready to Start Your Home Extension?
No pressure, no obligation — tell us a bit about your block and what you're after, and we'll come back with honest advice on scope, approvals and cost.
Financing your project? Ask us about staged payment structures aligned to build milestones — we're happy to talk through options.
Where We Work
Based in Subiaco, working across the western suburbs including Shenton Park, Daglish, Jolimont, Karrakatta, Nedlands, Claremont and the wider Perth metro area.
Read our full guide: House extension costs in Perth