Licensed Home Extension Builder Greenwich
NSW licensed extension specialist. Greenwich 2065 extensions on 1880s–1940s heritage-era homes require structural sign-off, Class M (sandstone ridges) / H–E (river fall) footings, and matched connection — we engineer and document properly.
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MBA NSW0476 300 300Quick Answer
A home extension in Greenwich costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Lane Cove Council approvals, and construction under one fixed-price contract.
Greenwich Home Extensions & Additions
Extension is the dominant scope in Greenwich given heavy heritage controls. Federation mansion additions on harbour-fall sites — suspended slabs, structural underpinning, foreshore consent. Realistic budget $550K–$1.6M for premium 80–140m² addition. Pre-construction 7–9 months.
Most Greenwich blocks run 500–1,200m² on Class M (sandstone ridges) / H–E (river fall) ground. Extension feasibility depends on what's underneath the existing slab and whether the frame can carry a second-storey load — Buildana checks both before quoting, so what's in the contract is what gets built. Median price band: $3.5M–$8.0M. Nearest rail is Wollstonecraft (1.5 km, ferry).
Buildana manages the complete home extension process in Greenwich — 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 Greenwich from $150K
- Lane Cove Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Class M (sandstone ridges) / H–E (river fall) soil — structural engineering included
- 1880s–1940s heritage-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Wollstonecraft (1.5 km, ferry) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Why Extend Your Home in Greenwich?
Greenwich is the harbour-fall peninsula between Greenwich Point, Manns Point and Bay Road on Sydney Harbour. Federation mansions, inter-war heritage and contemporary harbour-fall builds on 500–1,200m² blocks. Heritage Conservation Areas cover most streets. Sandstone-dominant with substantial harbour fall. North Sydney LGA boundary east at Wollstonecraft. Greenwich ferry wharf. Premium for direct harbour outlook.
Greenwich's established streetscape and median house prices of $3.5M–$8.0M reflect a premium location within Lane Cove. Building costs sit above the metro average, offset by stronger capital growth and rental returns. Transport access via Wollstonecraft (1.5 km, ferry) connects Greenwich to the wider Sydney network. 1880s–1940s heritage-era homes in Greenwich often have good structural foundations worth building on. Extensions add living space at a fraction of the full rebuild cost. Ground conditions (Class M (sandstone ridges) / H–E (river fall)) across Greenwich are well understood by local builders — Buildana's engineering accounts for extremely reactive soil movement.
Extensions are the dominant scope across the heritage harbour-fall peninsulas (Greenwich, Longueville, Northwood, Linley Point) where KDR is restricted. Federation mansion additions, sandstone terrace reconfiguration, river-fall heritage-grade work all common. Suspended slab engineering on river-fall sites; bushfire BAL upgrades on Lane Cove West and Riverview bush-edge lots. Heritage Council expects retention of stained glass, ornate plasterwork, marble fireplaces, slate roofing on protected streets. Realistic budget $400K–$1.4M for thoughtful 60–130m² addition; $700K–$2M for premium harbour-fall heritage-grade work.
Planning Controls — Lane Cove Council
Lane Cove LEP 2009 & Lane Cove DCP 2010. R2 Low Density dominates the LGA: FSR 0.5:1, building height 9.5m, front setback 7.5–9m varying by streetscape, landscaped area 35–40%. R3 Medium Density along Burns Bay Road, Longueville Road and the Lane Cove village core permits FSR up to 0.8:1. R4 High Density and B4 Mixed Use along the St Leonards / Crows Nest fringe in Lane Cove North. The 2024 Crows Nest Metro SEPP TOD precinct overlay reaches the south-eastern portion of Lane Cove North, opening density bonuses inside 400m of Crows Nest Metro station. Heritage Conservation Areas cover most older streets in Greenwich, Longueville, Northwood, Linley Point, Lane Cove West, Riverview and parts of Lane Cove village. Tree Preservation Order applies LGA-wide. River-fall and harbour-fall sites on the Lane Cove River and Sydney Harbour peninsulas (Greenwich, Longueville, Northwood, Linley Point) require engineered slab and retaining design — sandstone rock excavation $20K–$60K standard. Lane Cove National Park frontage on Lane Cove West and Riverview adds bushfire BAL ratings on bush-edge lots.
Home extension builder in Greenwich — key facts
- Suburb
- Greenwich, NSW 2065
- Council / LGA
- Lane Cove Council (Lane Cove)
- Primary zoning
- R2 Low Density / R3 Medium (Lane Cove village)
- Typical lot size
- 500–1,200m²
- Soil class
- Class M (sandstone ridges) / H–E (river fall)
- Median house price
- $3.5M–$8.0M
- Home era
- 1880s–1940s heritage
- 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
Building in Greenwich — Local Context
Foundations & Slab Design for Greenwich
Greenwich's ground is extremely reactive clay (Class M (sandstone ridges) / H–E (river fall)). On a 500–1,200m² block, that translates to engineered slab work in the $45,000–$80,000 bracket for a extension. Double-check any quote that doesn't itemise the slab — 'slab as per engineering' usually means the builder will hit you with a variation once the soil report comes back. We commission the geotech upfront, before pricing, so the cost in your contract reflects what your block actually needs. If your neighbour's home shows movement cracks above architraves or below window sills, that's a signal worth knowing before you finalise design — Buildana's site assessment looks at adjacent stock too.
Approval Timeline for Greenwich
Realistic timeline for a extension in Greenwich: 8–14 weeks for DA through Lane Cove Council. Add 2–4 weeks before lodgement for documentation, BASIX certificate, geotech report, and survey if you don't already have one. Construction Certificate is issued separately before works commence.
Cost vs Value in Greenwich
Median sale price in Greenwich is $3.5M–$8.0M. For a extension, the decision tree runs through three numbers: build cost, expected post-completion value, and how long you plan to hold. Ground-floor extensions of 30–50m² typically return 1.1–1.3× their cost at sale in suburbs around $3.5M–$8.0M. Second-storey adds tend to outperform — 1.3–1.6× — because they unlock larger family layouts on standard blocks. We map this in feasibility before you commit.
Greenwich Housing Stock & What That Means
Most homes in Greenwich were built 1880s–1940s heritage. That puts asbestos risk firmly in play — sheeting, eaves linings, vinyl floor tiles, and pipe lagging are likely. Licensed removal adds $5,000–$25,000 to a extension where demolition is involved, and Buildana manages SafeWork NSW notifications, removal, and clearance certificates as part of the contract. Existing structures from 1880s–1940s heritage usually need wiring, plumbing, and insulation upgrades to meet NCC 2025 — worth costing that into the extension scope upfront, not as a variation later.
Building Activity in Greenwich Right Now
Greenwich is seeing steady residential activity — extensions are picking up as families choose to upsize their existing home rather than face stamp duty on a move. Buildana sits inside that pipeline — we know what's getting approved, what's stalling, and why.
Builder's Take on Greenwich
Lane Cove Council setback and height rules apply to the extension, not the whole house. An older Greenwich home that was built inside the setback might not be extendable to the boundary. We check that during feasibility so there's no expensive surprise at DA stage.
Timing on Greenwich extensions typically runs 14–24 weeks for ground-floor additions, 20–32 weeks for second-storey. Living in the house during the build is possible but requires staging — we plan around it so the kitchen and main bathroom aren't out at the same time.
Greenwich vs Nearby Suburbs
Greenwich vs nearby suburbs — key metrics for extending.
| Suburb | Median Price | Typical Lot | Soil Class | Era | Station |
|---|---|---|---|---|---|
| Greenwich2065this suburb | $3.5M–$8.0M | 500–1,200m² | Class M (sandstone ridges) / H–E (river fall) | 1880s–1940s heritage | Wollstonecraft (1.5 km, ferry) |
| Wollstonecraft2065 | $2.8M–$4.5M | 400–700m² | Class M (sandstone) / H–E (Gore Cove fall) | 1900s–1960s | Wollstonecraft |
| Northwood2066 | $4.0M–$8.0M | 600–1,400m² | Class M (sandstone ridges) / H–E (river fall) | 1880s–1940s heritage | Wollstonecraft (3 km, ferry from Longueville) |
| St Leonards2065 | $2.2M–$3.2M | 350–600m² | Class M (ridges) / H to E (Middle Harbour valleys) | 1900s–2000s mixed | St Leonards |
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.
Have a question about your project?
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How It Works
From First Call to Final Key
The first job on an extension is finding out what you're extending onto. Greenwich homes from the 1880s–1940s heritage 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.
⏱Quality Promise
We extend Greenwich homes with a structural engineer on every job. Second storey, rear addition, multi-room — engineered and priced upfront.
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.
Our Team
Oliver Alameri
Founder / Director / Builder · MPropDev · PhD Student
Ahmad Alameri
Accounts Manager
Claire Wendell
Project Manager
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Fatima Al-Rashid
Liverpool, NSW
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Last updated: 1 April 2026
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