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Sydney 2026 Indicative Pricing

Home Extension & Second-Storey Cost Estimator

NSW Lic. 497435C No spam · Reply within one business day
1
What kind of extension?
Ground-floor pushes out the footprint. Second-storey adds up. Knock-down / rebuild defers to a quote.
Knock-down & rebuilds need a site visit and detailed scoping, they're too variable for a calculator. We'll send a fixed-price quote within 5 business days. Hit "Show my estimate" below to start that process.
2
Roughly what floor area are you adding?
A small bedroom is ~12 m². A new master + ensuite is ~25-35 m². A whole second storey is typically 60-100 m².
35m²
≈ 1 bedroom + ensuite
15 m²50 m²85 m²120 m²
3
What finish level?
Drives the per-m² rate. Most Sydney homeowners land in mid-tier.
4
Structural complexity
Tells us how much engineering, propping and groundworks are likely needed.
Heads up, underpinning risk: Second-storey additions on older Sydney homes (especially pre-1970s) commonly need underpinning at $1,500-$3,500 per linear metre. We always check with a structural engineer before we quote. Range widened to ±18% to account for it.
5
Wet areas inside the new space
Each adds a fixed range based on tier. Skip if it's just bedrooms / living.
6
Site factors
Tick anything that applies. These each push the build cost up.
Heritage / conservation overlays in Sydney typically add 6-15% to total cost (matching materials, council conditions, longer DA). We've widened the range to ±18% to reflect that variability.
7
Sydney postcode
Eastern Suburbs / Lower North Shore / Northern Beaches sit ~15% above the Sydney baseline; Inner West heritage pockets ~10% above.
Sydney baseline, enter postcode to refine
8
About your project (optional)
This doesn't change the price. It tells us what to cover when we talk it through.
When would you like to start?
Do you have plans yet?

Get a more detailed quote

Send your plans, drawings or photos and a few words about the job, and a builder will come back with a more detailed indicative quote. Prefer to talk? Just leave your mobile. We reply within one business day.

Plans, drawings or photos (optional)
PDF, JPG or PNG. Up to 5 files, 7 MB in total. Bigger files? Email them to us.
    Or call 0478 183 300
    How this estimator works: Per-m² rates are triangulated from published Sydney cost guides, the RLB Riders Digest 2026, the Archicentre CostGuide 2026, Altus, Master Builders and HIA NSW data, and the ABS producer price index. Suburb premiums reflect 2025-26 wage and material differentials. The headline figure includes GST, with the ex-GST equivalent shown beneath it. It covers the building work only. Numbers are indicative for budgeting only, a fixed-price quote requires a site visit, structural pre-check and detailed scoping.