Knockdown Rebuild Frenchs Forest — Demo to Handover in 12 Months
Frenchs Forest 2086 KDR with tight programme: demolition (3–4 weeks), new home (24–40 weeks). CDC fast-track or Northern Beaches Council DA. Weekly progress updates.
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A knockdown rebuild in Frenchs Forest 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.
Frenchs Forest Knockdown Rebuilds
KDR in Frenchs Forest works 600–900m² 1960s–1980s brick stock — Hawkesbury Sandstone, BAL-12.5 to BAL-29 on bushland-fringe lots, Northern Beaches Hospital adjacency. End values $2.2M–$3.4M. Pre-construction 5–8 months.
Most Frenchs Forest blocks run 600–900m² on Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts ground. Knockdown rebuild on 1960s–1980s stock here usually pencils out better than deep renovation once you tally up structural, electrical, plumbing, insulation, and waterproofing upgrades against full replacement value. Median price band: $2.2M–$3.4M. B-Line bus to CBD (Forest Way interchange) station services the suburb.
Buildana manages the complete knockdown rebuild process in Frenchs Forest — 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 Frenchs Forest from $450K
- Northern Beaches Council DA and CDC approvals managed
- Demolition and asbestos removal included
- Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts soil — engineered slab design included
- Typical blocks 600–900m² in Frenchs Forest
- Single and two-storey designs available
- 6-year structural warranty
- Free site assessment — near B-Line bus to CBD (Forest Way interchange) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Why Knockdown Rebuild in Frenchs Forest?
Frenchs Forest is the established bushland-fringe suburb anchored by Northern Beaches Hospital — 1960s–1980s brick on 600–900m² blocks with sandstone topography. BAL-12.5 to BAL-29 on bushland-fringe lots. Hawkesbury Sandstone with rock excavation $40K–$120K typical. Northern Beaches Hospital (opened 2018) drives medical-staff demand.
Frenchs Forest's rural-residential character and 600–900m² blocks set it apart from standard suburban development. R2 Low / R3 Medium (Manly, Dee Why, Brookvale, Mona Vale, Avalon town centres) / RU2 Rural Landscape (Ingleside, Terrey Hills, Duffys Forest, Oxford Falls) / E3/E4 Environmental on bushland fringe zoning means different controls apply — larger setbacks, on-site services, and site-specific engineering. Transport access via B-Line bus to CBD (Forest Way interchange) connects Frenchs Forest to the wider Sydney network. 1960s–1980s-era housing stock across Frenchs Forest is prime for knockdown rebuild — replacing dated layouts and materials with modern, NCC-compliant homes that maximise block potential. Ground conditions (Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts) across Frenchs Forest are well understood by local builders — Buildana's engineering accounts for extremely reactive soil movement.
KDR in the Northern Beaches splits sharply by tier. The premium oceanfront and harbour-front tier — Manly, Freshwater, Curl Curl, Collaroy, Narrabeen, Mona Vale, Newport, Avalon Beach, Bilgola Beach, Whale Beach, Palm Beach (oceanfront); Clontarf, Seaforth, Balgowlah Heights, Fairlight (harbour-front); Bayview, Church Point, Clareville (Pittwater-front) — runs end values $4M–$15M+ on direct waterfront, $2.5M–$6M+ on premium suburban. Hawkesbury Sandstone soil predominant — deep rock excavation $40K–$200K+ is LGA-defining; the Northern Beaches has the most rock-excavation territory of any Sydney LGA on a per-build basis. Bushfire-prone overlays are LGA-defining — BAL-12.5 to BAL-FZ across virtually all bushland-fringe lots (Belrose, Davidson, Killarney Heights, Frenchs Forest, Forestville, Beacon Hill, Cromer, Allambie Heights, Bayview, Church Point, Avalon, Bilgola Plateau, Whale Beach, Palm Beach, Clareville). RFS Bushfire Protection Assessment routine — non-combustible cladding, ember-screened openings, sprinklered eaves on BAL-FZ adding $40K–$120K. Coastal Hazard zones drive coastal-engineering reports on Pittwater Road oceanfront properties at Collaroy, Narrabeen, Curl Curl, Dee Why, Mona Vale, Palm Beach (2016 storm event reset baselines on Collaroy/Narrabeen). Coastal salt-grade specs (marine-grade fixings, sealed envelope, copper/zinc flashings, treated-pine timber) standard on every coastal-facing build — add $20K–$60K material premium. Coastal acid sulphate soils (CASS) on lagoon margins (Narrabeen Lagoon, Curl Curl Lagoon, Dee Why Lagoon, Manly Lagoon, Mona Vale Lagoon) drive specialist dewatering and acid neutralisation protocols. Heritage Conservation Areas extensive across the older village cores. Tree Preservation Order LGA-wide and strict. Demolition $40K–$90K with asbestos universal pre-1990. RU2 acreage at Ingleside, Terrey Hills, Duffys Forest, Oxford Falls runs AWTS on-site sewer and Sydney Drinking Water Catchment overlay (parts) — premium acreage end values $3.5M–$8M+. Realistic premium turnkey $1.8M–$3.2M for 280–450m² inland mid-tier (Brookvale, Dee Why, Cromer, Narraweena, Beacon Hill, Allambie Heights, Wheeler Heights); $2.5M–$5M on premium suburban (Balgowlah, Fairlight, Manly Vale, Forestville, Frenchs Forest, Belrose, Davidson); $4M–$10M+ on oceanfront/harbour-front (Manly, Clontarf, Seaforth, Balgowlah Heights, Curl Curl, Freshwater, Collaroy, Mona Vale, Newport, Avalon); $6M–$20M+ on Palm Beach/Whale Beach/Bilgola Beach direct beachfront. Pre-construction 5–8 months suburban; 8–14 months on bushfire-prone, coastal hazard, RU2 acreage or heritage sites.
Planning Controls — Northern Beaches Council
Northern Beaches LEP 2022 (consolidating the legacy Manly, Warringah and Pittwater LEPs) & Northern Beaches DCP. Post-2016 amalgamation LGA spanning the entire ocean-and-harbour peninsula from North Head to Barrenjoey — 252 km² with 36+ residential suburbs, four lagoons, the Garigal and Ku-ring-gai Chase National Parks, and the Pittwater estuary. R2 Low Density covers most residential streets: FSR 0.5–0.55:1, building height 8.5–9m, front setback 6–7.5m, landscaped area 40–60%, deep soil 25–35%. R3 Medium Density along Pittwater Road and around station precincts (no rail — B-Line bus equivalents at Manly, Brookvale, Dee Why, Collaroy, Narrabeen, Mona Vale interchange/terminus) permits FSR up to 0.9:1. R4 High Density and B4 Mixed Use concentrated on Manly town centre + the Corso, Dee Why town centre, Brookvale, Mona Vale town centre, Avalon village core. Northern Beaches DCP duplex minimum lot varies by precinct — 600m² (legacy Manly + Pittwater R2) to 700m² (legacy Warringah R2). RU2 Rural Landscape covers the rural acreage belt — Ingleside, Terrey Hills, Duffys Forest, Oxford Falls, parts of Belrose — restricting subdivision to 2ha+ minimum. E3 Environmental Management and E4 Environmental Living overlays on bushland-fringe lots backing Garigal NP, Ku-ring-gai Chase NP, Manly Dam Reserve and Narrabeen Lagoon catchment further restrict siting. Heritage Conservation Areas extensive — Manly heritage core (the Corso, Eastern Hill, North Head precinct), Fairlight, Balgowlah, Balgowlah Heights, Clontarf, Seaforth, Avalon village, Newport village, Mona Vale, Bilgola Beach cove, Whale Beach, Palm Beach village, Freshwater village (Duke Kahanamoku surfing precinct), Curl Curl heritage streets, Collaroy village, Narrabeen heritage streets. Aboriginal cultural heritage protocols apply across most sandstone country (extensive rock-art sites, middens, engravings) — pre-DA Aboriginal Cultural Heritage Assessment routine on bushland-fringe and waterfront sites. Tree Preservation Order LGA-wide and strict — Northern Beaches retains the most extensive remnant bushland of any Sydney LGA. Hawkesbury Sandstone soil predominant — deep rock excavation $40K–$200K+ is LGA-defining (the most rock-excavation territory of any Sydney LGA on a per-build basis). Class P/E coastal alluvial on Narrabeen Lagoon, Curl Curl Lagoon, Dee Why Lagoon, Manly Lagoon and Mona Vale Lagoon corridors — suspended slab + Class P/E footing engineering and dewatering required. Coastal acid sulphate soils (CASS) on lagoon margins drive specialist dewatering and acid neutralisation protocols. Coastal Hazard zones are LGA-defining — coastal erosion line affects Pittwater Road oceanfront properties at Collaroy, Narrabeen, Curl Curl, Dee Why, Mona Vale, Palm Beach (2016 storm event reset baselines on Collaroy/Narrabeen specifically; multiple oceanfront properties since required Council coastal-hazard reports for any DA). Bushfire-prone land overlays are LGA-defining — BAL ratings BAL-12.5 to BAL-FZ across virtually all bushland-fringe lots (Belrose, Davidson, Killarney Heights, Frenchs Forest, Forestville, Beacon Hill, Cromer, Allambie Heights, Oxford Falls, Terrey Hills, Duffys Forest, Ingleside, Bayview, Church Point, Avalon, Bilgola Plateau, Whale Beach, Palm Beach, Clareville, Newport bushland-fringe). RFS Bushfire Protection Assessment routine — non-combustible cladding, ember-screened openings, sprinklered eaves on BAL-FZ, Asset Protection Zone (APZ) 10–40m+ on most acreage. AWTS on-site sewer mandatory on RU2 acreage belt (no reticulated sewer on Ingleside/Terrey Hills/Duffys Forest/Oxford Falls). Sydney Drinking Water Catchment overlay on parts of Ingleside, Terrey Hills, Duffys Forest western edges and Pittwater foreshore — restricts AWTS dispersal field siting and adds NSW Health/WaterNSW referral. Riparian setbacks 10–60m on Narrabeen Lagoon, Curl Curl Lagoon, Dee Why Lagoon, Manly Lagoon, Mona Vale Lagoon, Pittwater foreshore, Cowan Creek tributaries, Middle Harbour and North Harbour. Foreshore Building Line restrictions on direct waterfront across Pittwater (Bayview, Church Point, Clareville, Avalon, Newport), Middle Harbour (Clontarf, Seaforth, Balgowlah Heights), North Harbour (Fairlight, Balgowlah Heights) and ocean cliffs (Manly, Freshwater, Curl Curl, Narrabeen, Mona Vale, Newport, Bilgola, Avalon, Whale Beach, Palm Beach). The LGA has no rail — B-Line bus is the primary spine (Mona Vale terminus through Warringah Mall Brookvale interchange to CBD via Mosman). Beaches Link Tunnel (under construction, opening 2028) is the LGA-defining infrastructure event — twin tunnels under Middle Harbour connecting Cammeray to Balgowlah/Seaforth with portals reshaping traffic and property values across Balgowlah, Balgowlah Heights, Seaforth, Manly Vale and Manly. Northern Beaches Hospital (opened 2018, Frenchs Forest) anchors LGA medical employment and drives granny flat hospital-staff demand on Frenchs Forest, Davidson, Allambie Heights, Forestville, Belrose. Manly Hospital site redevelopment under master plan. Mona Vale Hospital site (Northern Beaches Hospital amalgamation legacy) under redevelopment. Warriewood Valley Release Area is the LGA's only active master-planned new-release on R3/R4 medium-density 300–600m² lots. Ingleside Precinct master-plan rezoning (originally proposed for ~3,400 dwellings) under review/paused. The Corso, Manly is the heritage retail spine. Avalon, Newport, Mona Vale, Collaroy, Dee Why, Brookvale and Manly are the primary commercial centres. Premium clifftop ocean-view properties at Manly, Freshwater, Curl Curl, Avalon, Bilgola, Whale Beach, Palm Beach are among Australia's most expensive residential markets ($8M–$30M+ on Palm Beach alone).
Knockdown-rebuild builder in Frenchs Forest — key facts
- Suburb
- Frenchs Forest, NSW 2086
- Council / LGA
- Northern Beaches Council (Northern Beaches)
- Primary zoning
- R2 Low / R3 Medium (Manly, Dee Why, Brookvale, Mona Vale, Avalon town centres) / RU2 Rural Landscape (Ingleside, Terrey Hills, Duffys Forest, Oxford Falls) / E3/E4 Environmental on bushland fringe
- Typical lot size
- 600–900m²
- Soil class
- Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts
- Median house price
- $2.2M–$3.4M
- Home era
- 1960s–1980s
- 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
Building in Frenchs Forest — Local Context
What Frenchs Forest Soil Means for Your Rebuild
Most blocks across Frenchs Forest (2086) classify as Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts — extremely reactive clay. Translation for a knockdown rebuild: foundation cost lands somewhere between $45,000–$80,000, depending on building footprint and how the engineer reads the borehole. Reactive soils move with seasonal moisture. A waffle pod alone won't cut it on a Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts site — you need stiffened edge beams, sometimes piered footings, and careful detailing around wet areas to stop differential movement showing up as cracking. Buildana includes the geotech report, structural engineering, and slab design in every quote. No site allowance, no provisional sum.
Planning Controls in Frenchs Forest
Frenchs Forest is zoned R2 Low / R3 Medium (Manly, Dee Why, Brookvale, Mona Vale, Avalon town centres) / RU2 Rural Landscape (Ingleside, Terrey Hills, Duffys Forest, Oxford Falls) / E3/E4 Environmental on bushland fringe with R3 Medium Density pockets. Northern Beaches Council controls FSR, height limits (typically 8.5–9m), site coverage, landscaped area minimums, and setbacks. For a rebuild, the binding constraints on most 600–900m² blocks here are: front setback (around 4.5–6m), side setbacks (1.0–1.5m articulated), rear (3–6m depending on lot depth), and landscaped area (usually 35–40%). Buildana's design team works to those numbers from the first sketch — no late re-design when council comes back with comments.
Cost vs Value in Frenchs Forest
Median sale price in Frenchs Forest is $2.2M–$3.4M. For a rebuild, the decision tree runs through three numbers: build cost, expected post-completion value, and how long you plan to hold. New custom homes in Frenchs Forest re-set the property at the top of the local price band, with new-build premium of 10–20% over comparable established stock. We map this in feasibility before you commit.
Designing for the Frenchs Forest Streetscape
Frenchs Forest's housing stock is predominantly from the 1960s–1980s. B-Line bus to CBD (Forest Way interchange) station is the rail anchor for the suburb. The local anchor is Northern Beaches Hospital + Forest High School + Forest Way Shopping Centre. For a knockdown rebuild, the streetscape question matters more than most builders admit — a brand-new double-storey on a street of single-storey 1960s–1980s weatherboards will draw council attention on bulk and scale, even if technically compliant. Buildana designs the front elevation to read appropriately for the street while modernising the floor plan and structure behind it. Materials palette, roof pitch, fenestration rhythm — all chosen to settle into the existing rhythm rather than fight it.
Building Activity in Frenchs Forest Right Now
Frenchs Forest is seeing steady residential activity — 1960s–1980s-era stock is reaching end-of-life on dozens of streets, driving steady knockdown rebuild activity month over month. Buildana sits inside that pipeline — we know what's getting approved, what's stalling, and why.
Builder's Take on Frenchs Forest
One-contract KDR in Frenchs Forest vs two-contractor (demo + builder separately): two-contractor looks cheaper on paper but the site risk transfers to you between the crews. Old footings, buried tanks, boundary disputes — all your problem. Buildana's single contract keeps the risk with the contractor.
KDR maths in Frenchs Forest usually wins against deep renovation once renovation costs cross $300K. Below that, renovation is competitive. Above it, you're paying renovation pricing for a home that's still structurally 1970s. New build gives you 6-year warranty, NCC 2025 performance, and a genuine reset on property value.
Frenchs Forest vs Nearby Suburbs
Frenchs Forest vs nearby suburbs — key metrics for knocking down and rebuilding.
| Suburb | Median Price | Typical Lot | Soil Class | Era | Station |
|---|---|---|---|---|---|
| Frenchs Forest2086this suburb | $2.2M–$3.4M | 600–900m² | Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts | 1960s–1980s | B-Line bus to CBD (Forest Way interchange) |
| Forestville2087 | $2.2M–$3.4M | 600–900m² | Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts | 1950s–1980s + premium contemporary | B-Line bus to CBD (Frenchs Forest interchange) |
| Belrose2085 | $2.4M–$3.8M | 600–1,200m² | Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts | 1970s–1990s + premium contemporary | B-Line bus to CBD (Frenchs Forest interchange) |
| Davidson2085 | $2.4M–$3.6M | 600–1,000m² | Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts | 1960s–1980s + premium contemporary | B-Line bus to CBD (Frenchs Forest interchange) |
Median price, soil class, and lot size shape build feasibility and final cost. Buildana assesses every site against these and other constraints during the free feasibility stage.
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How It Works
From First Call to Final Key
KDR starts with an honest look at the existing house. Sometimes it's worth keeping. Most Frenchs Forest homes from the 1960s–1980s — especially fibro and brick-veneer — are beyond the point where renovation makes sense. We tell you straight.
⏱Demolition is pre-approved to run parallel with rebuild design. Asbestos cleared, services abolished, site stripped in a single mobilisation. Geotech reconfirms Class Hawkesbury Sandstone predominant (deep rock excavation $40K–$150K+ on most lots) / Class P/E coastal alluvial on Narrabeen/Curl Curl/Dee Why/Manly/Mona Vale lagoon corridors / coastal acid sulphate soils (CASS) on lagoon margins / coastal hazard zones on Collaroy–Narrabeen, Curl Curl, Dee Why, Manly, Mona Vale, Palm Beach beachfronts soil with the old house gone.
⏱New house goes up on the same footprint or a better one, whichever serves the block. Modern NCC envelope, better orientation, fit-for-purpose room sizes. The suburb stays the same; the house finally fits it.
⏱Final handover: new OC, six-year structural warranty, all the documentation on your Frenchs Forest block you'd get on a greenfield build. The only difference is you still live in the street you chose.
⏱Quality Promise
Frenchs Forest knockdown rebuild done cleanly: licensed demolition, compliant slab, new home built to NCC 2025. Fixed-price contract.
Cost Guide
| Item | Estimated Range |
|---|---|
| Clean demolition + standard rebuild | $540,000 – $840,000 |
| Asbestos-affected demolition + rebuild | $570,000 – $900,000 |
| Sloping site + cut/fill + rebuild | $630,000 – $1,010,000 |
| Heritage-affected or complex site | $670,000 – $1,230,000 |
| Premium finishes & architectural design | $1,060,000+ |
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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Last updated: 1 April 2026
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