Home Extension Cost in Sydney — 2026 Price Guide
A home extension in Sydney costs $150,000 to $600,000+ depending on scope, size, and complexity. Based on Rawlinson data adjusted for 2026 Sydney and Buildana's (Lic. 487805C) project experience across Western Sydney, here is what different extension types cost.
Extension Cost by Type
Rawlinson 2026 adjusted rates for Sydney:
Ground floor extension (rear or side): • 40–60 sqm, brick veneer: $2,280–$2,455/sqm (shell, excl. fit-out) • 60–100 sqm, brick veneer: $2,280–$2,455/sqm • Total for 60 sqm ground extension: $136,800–$147,300 + fit-out
First floor addition: • 60–100 sqm, brick veneer: $3,425–$3,690/sqm (shell, excl. fit-out) • Total for 80 sqm first floor: $274,000–$295,200 + fit-out
Fit-out costs (in addition to shell): • Kitchen: $24,375–$27,500 (medium quality) • Bathroom: $29,375–$33,125 (medium quality)
All-in examples: • Rear living extension (60 sqm) + new kitchen: $180,000–$220,000 • First floor master suite (40 sqm) + ensuite: $175,000–$220,000 • Ground + first floor (60 + 80 sqm) + kitchen + 2 bathrooms: $400,000–$520,000
Why First Floor Costs More per sqm
First floor additions cost 50–55% more per sqm than ground floor extensions. The reasons:
1. Structural reinforcement: the existing ground floor walls and foundation may need strengthening to carry the additional load — $20,000–$50,000 2. Scaffolding: full perimeter scaffolding for 8–12 weeks — $8,000–$15,000 3. Staircase: new internal staircase — $8,000–$20,000 4. Temporary roof removal: the existing roof is partially or fully removed and rebuilt — significant labour and weatherproofing cost 5. Crane access: materials lifted to first floor level — $3,000–$8,000
For the comparison between ground and first floor, see our ground vs first floor extension guide.
Getting an Accurate Extension Quote
Extension costs vary more than new builds because every existing house is different. The condition of the existing structure, the complexity of the junction between old and new, and the scope of renovation to the existing areas all affect cost.
Buildana provides fixed-price extension contracts after a thorough assessment of the existing building. No provisional sums on structural reinforcement or junction treatment — these are included in the fixed price.
Contact Buildana for a free extension assessment. For the complete extension guide, see our comprehensive guide to home extensions in Sydney.
