Knockdown Rebuild Seaforth — One Contract, Demo to Keys
Everything under one agreement in Seaforth 2092: demolition, asbestos removal, site prep, design, approvals, engineering, new home construction, landscaping and Occupation Certificate.
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MBA NSW0476 300 300Quick Answer
A knockdown rebuild in Seaforth costs $450,000–$1,200,000+. Standard single-storey from $450K, two-storey from $650K. Buildana manages demolition, Northern Beaches Council approvals, and construction under one fixed-price contract.
Knockdown Rebuild Builder in Seaforth
A knockdown rebuild in Seaforth is an ultra-premium Middle Harbour project — Federation, inter-war and contemporary on 600 to 1,500m² blocks with substantial sandstone fall to the harbour, and the Beaches Link tunnel portal set to lift connectivity when it opens.
Deep rock excavation of $60,000 to $150,000 is typical, and the harbour fall means suspended slabs and substantial retaining on the fall lots, all priced from a real geotech bore. Heritage Conservation Areas cover the older streets.
The pre-war stock carries asbestos and lead paint, so a licensed strip-out leads the demolition.
We rebuild fixed-price, licence HBL 487805C. Get our feasibility, with the deep rock and fall costed, before you commit.
Buildana manages the complete knockdown rebuild process in Seaforth — from site assessment and architectural design through to DA or CDC approval, demolition management, and fixed-price construction to handover. One builder, one contract, one new home.
Read our KDR Cost Guide 2026 or use the Renovation vs KDR Calculator to compare options.
- New home in Seaforth from $450K
- Northern Beaches Council DA and CDC approvals managed
- Demolition and asbestos removal included
- Hawkesbury Sandstone — engineered slab design included
- Typical blocks 600–1,500m² in Seaforth
- Single and two-storey designs available
- 6-year structural warranty
- Free site assessment — near B-Line bus to CBD via Mosman + Beaches Link Tunnel (opening 2028) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
A premium harbour peninsula, better connected
Seaforth's 600 to 1,500m² blocks fall to Middle Harbour in one of the Beaches' premium harbour-front markets, and the Beaches Link tunnel portal will lift connectivity when it opens. A rebuild designs a substantial home around the harbour outlook.
It is an address where the build has to match the setting.
Deep rock, fall and heritage
Deep rock excavation of $60,000 to $150,000 is typical, with suspended slabs and substantial retaining on the fall lots — all priced from a real geotech bore. Heritage Conservation Areas cover the older streets.
The pre-war stock carries asbestos and lead paint, so a licensed strip-out leads the demolition.
Knockdown-rebuild builder in Seaforth — key facts
- Suburb
- Seaforth, NSW 2092
- Council / LGA
- Northern Beaches Council (Northern Beaches)
- Primary zoning
- R2 Low
- Typical lot size
- 600–1,500m²
- Soil class
- Hawkesbury Sandstone
- Median house price
- $3.5M–$10M+ (harbour-front)
- Home era
- 1900s–1940s heritage + premium contemporary
- Typical price range
- $450,000 – $1,200,000+
- Typical timeline
- 14–22 months including demolition
- Approval pathway
- CDC where eligible or DA for complex sites
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
Site visit covers everything that affects the build cost: vehicle access for trucks and crane, services (sewer depth, water connection, electrical service rating), soil exposure for borehole, neighbouring construction, and any obvious heritage or tree constraints. Real numbers, not estimates.
⏱Architectural design for your replacement home, structural engineering for Class Hawkesbury Sandstone soil, BASIX certification, and all approval documentation. Lodged as CDC (10–15 days) or DA (40–90 days) depending on design.
⏱Demolition runs 5–10 working days for a standard Seaforth cottage — longer if asbestos volume is significant or the structure includes a brick chimney or solid-block walls. Asbestos work happens first under a controlled removal program before mechanical demo starts.
⏱New home built from engineered slab (Class Hawkesbury Sandstone soil) to keys — fixed-price, milestone-based progress payments. Your project manager provides weekly updates.
⏱Walk through your finished home on your original Seaforth block. OC issued, all services live, 6-year structural warranty, appliance manuals, and maintenance schedule. Move in.
⏱Quality Promise
Seaforth KDR projects run on one contract: demolition, asbestos clearance, approvals, construction, handover. One builder accountable.
Cost Guide
| Item | Estimated Range |
|---|---|
| Entry-level single storey KDR | $600,000 – $810,000 |
| Mid-range double storey KDR | $900,000 – $1,250,000 |
| Architectural KDR | $1,250,000 – $1,880,000 |
| Luxury KDR (high-spec finishes) | $1,880,000+ |
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
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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