Licensed Home Extension Builder Double Bay
NSW licensed extension specialist. Double Bay 2028 extensions on 1900s–1940s + apartments-era homes require structural sign-off, Class M footings, and matched connection — we engineer and document properly.
HIA Member
MBA NSW0476 300 300Double Bay Home Extensions — Fixed Price
A home extension in Double Bay is built to a village standard that does not bend. Heritage homes sit on 250 to 1,000m² blocks, and the Bay Street postcode expects the wing to work behind the conserved fabric with finishes that match the market around it — anything that reads as cut-price undercuts the whole address.
The heritage areas are checked before design, and where the blocks drop toward the harbour the fall is engineered rather than assumed. Pre-war fabric gets the lead and asbestos handled under licence throughout.
At a $4.5M to $15M median, an exact wing is the only kind worth building — done to the standard, the addition shares in the premium; done cheaply, it drags on it.
We build these fixed-price, licence HBL 487805C. Get our extension scope, with heritage and fall resolved, before you commit.
Buildana manages the complete home extension process in Double Bay — from design consultation and structural engineering through to DA or CDC approval, and fixed-price construction to handover. Extend your home without the stress.
Read our Home Extension Cost Guide 2026 or explore extension approval pathways in NSW.
- Home extensions in Double Bay from $150K
- Woollahra Municipal Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- M — structural engineering included
- 1900s–1940s + apartments-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Edgecliff (1 km, ferry to Circular Quay) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
The postcode sets the bar
Double Bay's values demand the wing be exact — conserved heritage fabric, interiors and additions finished to the village standard, the harbour fall worked where it applies.
Done to that bar, the addition shares in the premium rather than diluting it.
Heritage and older fabric handled
The heritage areas are checked before design so the approval path is clear before you spend on drawings.
Lead paint travels with asbestos through the licensed pre-war handling, all priced into the job from the outset.
Home extension builder in Double Bay — key facts
- Suburb
- Double Bay, NSW 2028
- Council / LGA
- Woollahra Municipal Council (Woollahra)
- Primary zoning
- R2 Low
- Typical lot size
- 250–1,000m²
- Soil class
- M
- Median house price
- $4.5M–$15M
- Home era
- 1900s–1940s + apartments
- Typical price range
- $150,000 – $600,000+
- Typical timeline
- 6–12 months design to handover
- Approval pathway
- CDC for most rear extensions, DA for second-storey
Want a real number for YOUR block — not a generic estimate?
Free site assessment, fixed-price contract, line-itemised quote within 48 hours. No high-pressure sales — just a real builder talking real numbers.
Quality Promise
Buildana's Double Bay home extension process: assess the existing structure, design the addition, approve, build. Fixed price throughout.
How It Works
From First Call to Final Key
Everything that has to be right before we touch the ground. On-site assessment of your 1900s–1940s + apartments-era home in Double Bay. We check structural condition, block dimensions (250–1,000m²), setback availability, and Woollahra Municipal Council's DCP requirements. Written feasibility and cost estimate provided. Designing an extension is half about the new space and half about how it joins the old one. Doorway position, ceiling height transition, floor level matching, light wells — the junction makes or breaks how the finished home feels.
⏱The Double Bay construction phase. Fixed price, programmed, supervised. We lodge your extension approval — CDC for eligible designs or DA through Woollahra Municipal Council. Full documentation including structural engineering for Class M soil, BASIX, and shadow diagrams. CC issued before works start. For ground-floor rear extensions you usually stay in the house during the build, with temporary weatherproofing at the junction wall until the new section is locked up. Second-storey additions need a 4–8 week relocation during the roof-off and frame-up phase.
⏱The job isn't done when the site's clean; it's done when you have keys, certificates and warranties. Final inspection, Occupation Certificate, 6-year structural warranty. Your Double Bay home now has the space your family needs.
⏱Our Team
Oliver Alameri
Founder / Director / Builder · MPropDev · PhD Student
Ahmad Alameri
Accounts Manager
Claire Wendell
Project Manager
Estimate Your Build Cost
Use our free calculator to get an instant cost estimate for your project
Still got questions? Talk to Oliver directly.
30-min free call — bring your block, your brief, your budget. We'll map out feasibility, timeline, and realistic cost. No sales pitch.
Frequently Asked Questions
Buildana built our granny flat in just 12 weeks. Fast approvals, great communication, and a beautiful final product. Highly recommend.
Fatima Al-Rashid
Liverpool, NSW
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Headquartered in Western Sydney's Fairfield. Active across all 28 metropolitan Sydney LGAs — from Penrith to the Eastern Suburbs, the Hills to the Sutherland Shire.
Last updated: 1 April 2026
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