Home Extension Builder Rose Bay — Approved in 60 Days
Rose Bay 2029 extensions with tight approval timelines. CDC where eligible (~15 days), DA via Woollahra Municipal Council in 40–60 days. Construction 12–24 weeks depending on scope.
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MBA NSW0476 300 300Quick Answer
A home extension in Rose Bay costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Woollahra Municipal Council approvals, and construction under one fixed-price contract.
Rose Bay Home Extensions & Additions
A home extension in Rose Bay is usually a play for the harbour. This beachside village on the eastern harbour runs Federation mansions and inter-war homes on 300 to 1,500m² blocks with substantial fall to the water, and a well-placed upper level can claim an outlook that commands a serious premium in a $4.5M to $15M market. The slope and the heritage decide every term of the job.
Heritage Conservation Areas cover most streets, so street-facing changes get examined closely while rear and set-back upper work moves more freely. The ground is sandstone-dominant with harbour fall, so engineered slabs and rock excavation are standard rather than optional, and salt air off the beach means materials get specified for it. At these values, engineering it properly is the only approach that makes sense.
What I would check first on your Rose Bay block: the heritage status, the harbour fall and how the addition sits on it, and the sandstone in the dig. Those set the design and budget.
We build these fixed-price, licence HBL 487805C. Show us how it falls and we will design to it.
Buildana manages the complete home extension process in Rose 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 Rose 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 (4 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
A play for the harbour
This beachside village on the eastern harbour runs Federation mansions and inter-war homes on 300 to 1,500m² blocks with substantial fall to the water.
A well-placed upper level can claim an outlook that commands a serious premium in a $4.5M to $15M market, so the slope and heritage decide the job.
Heritage, sandstone and salt
Heritage Conservation Areas cover most streets, so street-facing changes get examined while rear and set-back upper work moves more freely.
The sandstone-dominant ground with harbour fall makes engineered slabs and rock excavation standard, and salt air off the beach means materials get specified for it.
Home extension builder in Rose Bay — key facts
- Suburb
- Rose Bay, NSW 2029
- Council / LGA
- Woollahra Municipal Council (Woollahra)
- Primary zoning
- R2 Low
- Typical lot size
- 300–1,500m²
- 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.
How It Works
From First Call to Final Key
The first job on an extension is finding out what you're extending onto. Rose Bay homes from the 1900s–1940s + apartments were built to different standards — we open walls, check footings, verify load paths. The existing house has to carry the new work.
⏱Design follows the existing roof. A bad extension looks like a bolt-on; a good one reads as original. Matched brickwork or contrasting render (whichever the architecture calls for), tied-in roofline, continuous flooring where it should be continuous.
⏱Construction happens while you live in the house. That means weatherproofing every night, staging the works so kitchens and bathrooms don't disappear on the same week, and keeping the site clean of debris that doesn't belong in a family home.
⏱Finish is seamless. Paint match, floor match, roofline match, brick match where possible. The only way to tell the extension is new is the date on the plans.
⏱Quality Promise
Buildana's Rose Bay home extension process: assess the existing structure, design the addition, approve, build. Fixed price throughout.
Cost Guide
| Item | Estimated Range |
|---|---|
| Simple rear extension (single wall removal, no roof change) | $126,000 – $280,000 |
| Moderate extension (multiple openings, roof extended) | $280,000 – $530,000 |
| Complex extension (structural steel portals, re-roofing) | $530,000 – $840,000 |
| Second-storey tie-in (existing house re-engineered) | $490,000 – $910,000 |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
Our Team
Oliver Alameri
Founder / Director / Builder · MPropDev · PhD Student
Ahmad Alameri
Accounts Manager
Claire Wendell
Project Manager
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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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Free design consultation for Rose Bay 2029. We'll assess your home, design the extension, and provide a fixed-price quote.
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Other Buildana services in Rose Bay
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Rose Bay 2029. Woollahra Municipal Council regulations and local controls are covered on each page.