Thornleigh Knockdown Rebuild — Stay on Your Street
Buildana handles KDR across Thornleigh 2120. 1900s–1940s Federation heritage (Beecroft/Cheltenham/Pennant Hills/Wahroonga boundary) + 1960s–1990s brick (Cherrybrook/Asquith/Mount Colah/Mount Kuring-gai) + 2010s+ R3/R4 redevelopment around Hornsby/Asquith/Waitara stations homes on 700–1,200m² typical (Hornsby/Asquith/Pennant Hills/Beecroft/Wahroonga boundary/Cherrybrook); 1–5ha acreage (Galston/Berrilee/Arcadia/Forest Glen/Glenorie/Berowra Heights bushland fringe) blocks — we know the soil, the Hornsby Shire Council rules, and the neighbours' expectations.
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MBA NSW0476 300 300Quick Answer
A knockdown rebuild in Thornleigh costs $450,000–$1,200,000+. Standard single-storey from $450K, two-storey from $650K. Buildana manages demolition, Hornsby Shire Council approvals, and construction under one fixed-price contract.
Thornleigh KDR — Single Contract, New Home
A knockdown rebuild in Thornleigh is a strong family play — Federation cottages and 1960s-90s brick on generous 600 to 1,000m² R2 blocks, with its own station, the marketplace and good schools. The aging stock and generous blocks suit a substantial modern rebuild.
Along the Pacific Highway, the R3 can make medium-density the bigger play on qualifying blocks. The Hawkesbury Sandstone bedrock means rock of $30,000 to $120,000, priced from a geotech bore, and some bushland-fringe lots carry BAL ratings.
The older stock can carry asbestos, so a licensed strip-out leads the demolition where needed. The 600m² duplex minimum puts a dual-occupancy in play on most blocks.
We rebuild fixed-price, licence HBL 487805C. Get our feasibility, with the rock and zoning checked, before you commit.
Buildana manages the complete knockdown rebuild process in Thornleigh — 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 Thornleigh from $450K
- Hornsby Shire Council DA and CDC approvals managed
- Demolition and asbestos removal included
- Hawkesbury Sandstone bedrock — engineered slab design included
- Typical blocks 700–1,200m² typical (Hornsby/Asquith/Pennant Hills/Beecroft/Wahroonga boundary/Cherrybrook); 1–5ha acreage (Galston/Berrilee/Arcadia/Forest Glen/Glenorie/Berowra Heights bushland fringe) in Thornleigh
- Single and two-storey designs available
- 6-year structural warranty
- Free site assessment — near Thornleigh station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Generous family blocks
Thornleigh's 600 to 1,000m² blocks, its own station, the marketplace and good schools make it a strong family rebuild suburb. The aging Federation-to-brick stock suits a substantial modern rebuild, and most blocks clear the 600m² duplex minimum.
Along the Pacific Highway, the R3 can make medium-density the bigger play — I check first.
Rock, fringe bushfire and old stock
The sandstone bedrock means rock of $30,000 to $120,000, priced from a geotech bore, with BAL ratings on some bushland-fringe lots checked on the mapping.
The older stock can carry asbestos, so a licensed strip-out leads the demolition where needed.
Knockdown-rebuild builder in Thornleigh — key facts
- Suburb
- Thornleigh, NSW 2120
- Council / LGA
- Hornsby Shire Council (Hornsby Shire)
- Primary zoning
- R2 Low Density predominant
- Typical lot size
- 700–1,200m² typical (Hornsby/Asquith/Pennant Hills/Beecroft/Wahroonga boundary/Cherrybrook); 1–5ha acreage (Galston/Berrilee/Arcadia/Forest Glen/Glenorie/Berowra Heights bushland fringe)
- Soil class
- Hawkesbury Sandstone bedrock
- Median house price
- $1.8M–$2.6M Hornsby/Asquith/Mount Colah; $2.4M–$3.6M Cherrybrook/Beecroft/Pennant Hills; $3.0M–$8.0M+ Galston/Arcadia acreage
- Home era
- 1900s–1940s Federation heritage
- 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.
Cost Guide
| Item | Estimated Range |
|---|---|
| Entry-level single storey KDR | $480,000 – $650,000 |
| Mid-range double storey KDR | $720,000 – $1,000,000 |
| Architectural KDR | $1,000,000 – $1,500,000 |
| Luxury KDR (high-spec finishes) | $1,500,000+ |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
How It Works
From First Call to Final Key
We assess your Thornleigh block — lot size (typical 700–1,200m² typical (Hornsby/Asquith/Pennant Hills/Beecroft/Wahroonga boundary/Cherrybrook); 1–5ha acreage (Galston/Berrilee/Arcadia/Forest Glen/Glenorie/Berowra Heights bushland fringe)), R2 Low Density predominant zoning, setbacks, FSR, and existing dwelling condition. Asbestos survey included. You'll know feasibility and budget before committing.
⏱Complete design package: floor plans, elevations, 3D renders, structural engineering, geotech, BASIX, stormwater, and all documentation Hornsby Shire Council requires. Approval managed start to finish.
⏱Pre-demolition: dilapidation report on adjoining properties (protects you against unfounded damage claims), service disconnections, asbestos clearance, neighbour notification. Then 1–2 weeks of physical demolition with material sorted at site for recycling where possible.
⏱Fixed-price construction: engineered slab, frame, lock-up, fit-out, external works. 8–12 months depending on size. Weekly progress reports with photos and milestone tracking.
⏱Same address, completely different home. Permanent gas, water, electrical, NBN reconnected and tested. Council waste collection re-registered. Mailbox reinstalled. Move-in ready, not move-in plus 100 small jobs.
⏱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 Thornleigh
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Thornleigh 2120. Hornsby Shire Council regulations and local controls are covered on each page.