Home Extension Builder Allambie Heights — Approved in 60 Days
Allambie Heights 2100 extensions with tight approval timelines. CDC where eligible (~15 days), DA via Northern Beaches Council in 40–60 days. Construction 12–24 weeks depending on scope.
HIA Member
MBA NSW0476 300 300Quick Answer
A home extension in Allambie Heights costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Northern Beaches Council approvals, and construction under one fixed-price contract.
Home Extension Builder in Allambie Heights
A home extension in Allambie Heights works the ridge — 1960s-1980s homes on 600 to 900m² blocks where the fall opens district and ocean glimpses one level up, and the premium replacements around you set the finish standard.
The sandstone is read before any dig, the bush-edge lots get the BAL assessment, and the era fabric gets licensed handling.
At the $2.4M to $3.6M median, the wing beats surrendering the ridge position to move.
We build these fixed-price, licence HBL 487805C. Ask us to measure what your block can hold.
Buildana manages the complete home extension process in Allambie Heights — 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 Allambie Heights from $150K
- Northern Beaches Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Hawkesbury Sandstone — structural engineering included
- 1960s–1980s + 2010s+ premium replacements-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near B-Line bus to CBD via Mosman / Brookvale (3 km) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
The ridge gives the direction
Allambie Heights' fall puts district and ocean glimpses one storey up — and where the block's orientation offers them, the first-floor addition earns its cost in the view alone.
The flatter blocks take generous rear wings instead, priced against the rock.
Bush edges and era handled
BAL ratings apply against the reserve boundaries, the sandstone is read before excavation, and the era fabric gets licensed handling.
The BAL materials, the rock read and the licensed removal are all in the fixed price.
Home extension builder in Allambie Heights — key facts
- Suburb
- Allambie Heights, NSW 2100
- Council / LGA
- Northern Beaches Council (Northern Beaches)
- Primary zoning
- R2 Low
- Typical lot size
- 600–900m²
- Soil class
- Hawkesbury Sandstone
- Median house price
- $2.4M–$3.6M
- Home era
- 1960s–1980s + 2010s+ premium replacements
- 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.
Cost Guide
| Item | Estimated Range |
|---|---|
| Simple rear extension (single wall removal, no roof change) | $99,000 – $220,000 |
| Moderate extension (multiple openings, roof extended) | $220,000 – $420,000 |
| Complex extension (structural steel portals, re-roofing) | $420,000 – $660,000 |
| Second-storey tie-in (existing house re-engineered) | $390,000 – $720,000 |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
How It Works
From First Call to Final Key
The first job on an extension is finding out what you're extending onto. Allambie Heights homes from the 1960s–1980s + 2010s+ premium replacements 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.
⏱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
We Build Across Sydney
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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Allambie Heights Extension — Free Consultation
Free design consultation for Allambie Heights 2100. We'll assess your home, design the extension, and provide a fixed-price quote.
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Other Buildana services in Allambie Heights
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Allambie Heights 2100. Northern Beaches Council regulations and local controls are covered on each page.