Sydney 2026 Indicative Pricing

Home Extension & Second-Storey Cost Estimator

Based on Sydney 2026 Quantity Surveyor data, Master Builders cost guides and our own real project numbers. Pick your scope below, get an indicative range before you call anyone.

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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
How this estimator works: Per-m² rates are triangulated from RLB & Altus 2026 cost guides, Master Builders / HIA NSW data, the ABS PPI, and Tillow Built's actual completed projects. Suburb premiums reflect 2025-26 wage and material differentials. Numbers are indicative for budgeting only, a fixed-price quote requires a site visit, structural pre-check and detailed scoping.