Home Extension Builder Bilgola Beach — From $150K Fixed Price
Fixed-price home extensions in Bilgola Beach 2107. Rear extension $150K–$300K, second storey $300K–$500K. Northern Beaches Council approvals managed. Free site consult.
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MBA NSW0476 300 300Quick Answer
A home extension in Bilgola Beach 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.
Second-Storey & Rear Additions in Bilgola Beach
A home extension in Bilgola Beach answers to the amphitheatre — the beach's enclosed valley holds heritage cottages, Sydney School modernism and contemporary builds, and the addition is designed to the house's own language.
The escarpment fall shapes the engineering, salt-grade materials are standard at the sand, and the modernist stock gets additions that respect what it is.
In a market running $4.5M to $15M+ on the oceanfront, the extension is built to conservation-grade standards.
We build these fixed-price, licence HBL 487805C. Walk us over the block and we will design to it.
Buildana manages the complete home extension process in Bilgola Beach — 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 Bilgola Beach from $150K
- Northern Beaches Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Hawkesbury Sandstone — structural engineering included
- 1920s–1960s heritage + Sydney School modernist + premium contemporary-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 (Avalon interchange) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
The house sets the language
Bilgola's valley holds three architectures — beach cottages, Sydney School modernism, contemporary builds — and the addition speaks the house's language or it fails the street.
The modernist stock in particular deserves extensions that respect what it is.
Fall, salt and rock
The escarpment fall shapes the structure, the sandstone is read before the dig, and salt-grade materials are standard at the sand.
All of it is engineered and costed before the budget is locked.
Home extension builder in Bilgola Beach — key facts
- Suburb
- Bilgola Beach, NSW 2107
- Council / LGA
- Northern Beaches Council (Northern Beaches)
- Primary zoning
- R2 Low
- Typical lot size
- 600–1,500m²
- Soil class
- Hawkesbury Sandstone
- Median house price
- $4.5M–$15M+ (oceanfront)
- Home era
- 1920s–1960s heritage + Sydney School modernist + premium contemporary
- 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) | $115,000 – $260,000 |
| Moderate extension (multiple openings, roof extended) | $260,000 – $490,000 |
| Complex extension (structural steel portals, re-roofing) | $490,000 – $770,000 |
| Second-storey tie-in (existing house re-engineered) | $450,000 – $830,000 |
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. Bilgola Beach homes from the 1920s–1960s heritage + Sydney School modernist + premium contemporary 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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Other Buildana services in Bilgola Beach
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Bilgola Beach 2107. Northern Beaches Council regulations and local controls are covered on each page.