Home Extension Builder Cremorne — From $150K Fixed Price
Fixed-price home extensions in Cremorne 2090. Rear extension $150K–$300K, second storey $300K–$500K. North Sydney Council approvals managed. Free site consult.
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A home extension in Cremorne costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, North Sydney Council approvals, and construction under one fixed-price contract.
Extending Homes in Cremorne
Extension in Cremorne works detached pockets along Military Road side streets — Federation and inter-war stock with character expected retained. Apartment renovations are the other major category given dominant strata stock. Heritage Conservation Areas restrict external scope. Realistic budget $400K–$1M for character work; $250K–$500K for apartment-scale internal reconfiguration.
On the ground in Cremorne (2090), the practical numbers shape every home extension. Class M (sandstone ridges) / H to E (harbour fall) soil — extremely reactive clay — pushes engineered foundation work into the $45,000–$80,000 bracket on most 350–600m² blocks. R3 Medium / R4 / B4 mixed zoning under North Sydney Council sets the building envelope, with R3 Medium Density pockets that open up dual occupancy options on qualifying lots. Median sale price across Cremorne sits at $2.5M–$4.0M, which frames the build-versus-buy decision from the start. Nearest rail is North Sydney (3 km), and that proximity affects everything from rental demand to construction site access.
Buildana manages the complete home extension process in Cremorne — 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 Cremorne from $150K
- North Sydney Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Class M (sandstone ridges) / H to E (harbour fall) soil — structural engineering included
- 1900s–1960s detached + apartments 1960s+-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near North Sydney (3 km) 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 Cremorne?
Cremorne occupies the ridge between Mosman Bay and Shell Cove with the Military Road spine running through. Mostly apartments and townhouses 1960s–2000s, with pockets of Federation and inter-war detached on side streets. Mosman LGA on the eastern boundary. Bus to North Sydney for rail; Mosman Bay ferry close. Premium for water glimpses and the lower north shore lifestyle.
Cremorne's established streetscape and median house prices of $2.5M–$4.0M reflect a premium location within North Sydney. Building costs sit above the metro average, offset by stronger capital growth and rental returns. Transport access via North Sydney (3 km) connects Cremorne to the wider Sydney network. 1900s–1960s detached + apartments 1960s+-era homes in Cremorne often have good structural foundations worth building on. Extensions add living space at a fraction of the full rebuild cost. Class M (sandstone ridges) / H to E (harbour fall) soil (extremely reactive) is standard for Cremorne — Buildana includes engineered slab design in every quote.
Extensions in North Sydney are mostly heritage-sensitive — Federation and inter-war terraces, cottages and harbourside mansions in Kirribilli, Lavender Bay, McMahons Point, Milsons Point, Cammeray, Neutral Bay, Waverton, Wollstonecraft and Cremorne. Council expects retention of heritage detail (stone walls, leadlight, slate roofs, decorative plasterwork) on character work. Second-storey additions on harbour-fall lots are engineering-intensive — suspended slabs, structural underpinning, harbour-view setback negotiation. Crows Nest Metro 2024 SEPP affects the Crows Nest extension scene with redevelopment pressure. Realistic budget $400K–$1.2M for a thoughtful 60–120m² heritage-grade addition; $300K–$700K for simpler post-war stock outside heritage zones.
Planning Controls — North Sydney Council
North Sydney LEP 2013 & North Sydney DCP 2013. R3 Medium Density dominates much of the LGA: FSR up to 0.85:1, building height 8.5–12m varying by precinct. R4 High Density along the North Sydney CBD edge and the Victoria Cross Metro 2024 SEPP precinct permits substantially higher FSR and height. B3/B4 mixed-use zones along Pacific Highway, Miller Street and Military Road. R2 pockets exist in Cammeray, Cremorne, Neutral Bay and parts of Waverton/Wollstonecraft with FSR 0.5:1 and minimum 9m frontage. Heritage Conservation Areas cover virtually all of Kirribilli, Lavender Bay, McMahons Point and Milsons Point, plus pockets of Cammeray, Neutral Bay, North Sydney, Waverton, Wollstonecraft and Cremorne. Tree Preservation Order applies LGA-wide. The 2024 Victoria Cross Metro SEPP TOD precinct opens density bonuses inside 400m of Victoria Cross Metro station — major redevelopment opportunity in central North Sydney. Crows Nest Metro 2024 SEPP also affects the Crows Nest portion of the LGA. Substantial harbour-fall sites on Kirribilli, Milsons Point, McMahons Point, Lavender Bay, Waverton, Cremorne Point and Kurraba Point require engineered slab and retaining design.
Home extension builder in Cremorne — key facts
- Suburb
- Cremorne, NSW 2090
- Council / LGA
- North Sydney Council (North Sydney)
- Primary zoning
- R3 Medium / R4 / B4 mixed
- Typical lot size
- 350–600m²
- Soil class
- Class M (sandstone ridges) / H to E (harbour fall)
- Median house price
- $2.5M–$4.0M
- Home era
- 1900s–1960s detached + apartments 1960s+
- 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 Cremorne — Local Context
What Cremorne Soil Means for Your Extension
Most blocks across Cremorne (2090) classify as Class M (sandstone ridges) / H to E (harbour fall) — extremely reactive clay. Translation for a home extension: 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 M (sandstone ridges) / H to E (harbour fall) 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.
North Sydney Planning Context
North Sydney has its own LEP and DCP layered over State planning controls. For extending in Cremorne, the practical impact: North Sydney Council's DCP sets local rules for streetscape character, materials palette in some precincts, vehicle crossover widths, and tree retention. R3 Medium / R4 / B4 mixed zoning on most Cremorne blocks permits single dwellings, alterations, and additions. Buildana checks every overlay (heritage, bushfire, flood, acid sulfate soil, biodiversity) before quoting.
Realistic Budget for Cremorne
For a home extension in Cremorne, the budget conversation starts with what you actually want versus what the site supports. Most quotes you'll get from volume builders strip out the things that matter on Class M (sandstone ridges) / H to E (harbour fall) soil — engineered slab upgrade, decent waterproofing, real drainage design, BASIX-compliant glazing — and present them as variations after you sign. We don't do that. Buildana's contract is fixed-price including everything required to deliver a extension that complies with NCC 2025 on a 350–600m² block in Cremorne.
Cremorne Housing Stock & What That Means
Most homes in Cremorne were built 1900s–1960s detached + apartments 1960s+. 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 1900s–1960s detached + apartments 1960s+ usually need wiring, plumbing, and insulation upgrades to meet NCC 2025 — worth costing that into the extension scope upfront, not as a variation later.
Realistic Cremorne Timeline
End-to-end timeline for a home extension in Cremorne, lodgement-realistic: 8-14 weeks for DA, depending on neighbour notification and any RFI rounds. Add 2-3 weeks for documentation pack assembly before lodgement (BASIX, geotech for Class M (sandstone ridges) / H to E (harbour fall), contour survey, hydraulic). Add 1 week for Construction Certificate post-approval. Construction runs 3-6 months depending on scope. Buildana provides a dated programme in every contract, not a vague "12-18 months" range.
Builder's Take on Cremorne
The cost-per-square-metre on an extension is almost always higher than new build — roughly $3,800–$5,500/m² vs $3,200–$4,500/m² for new. Reason: connecting new to old adds engineering, matching adds material cost, working around occupation adds time. Budget accordingly.
Existing-structure assessment is the non-negotiable first step. Cremorne 1900s–1960s detached + apartments 1960s+ homes often have undersized footings or termite-damaged wall plates that won't carry a second storey. We check with drilled inspections before quoting — no point designing a dream that's not structurally viable.
Cremorne vs Nearby Suburbs
Cremorne vs nearby suburbs — key metrics for extending.
| Suburb | Median Price | Typical Lot | Soil Class | Era | Station |
|---|---|---|---|---|---|
| Cremorne2090this suburb | $2.5M–$4.0M | 350–600m² | Class M (sandstone ridges) / H to E (harbour fall) | 1900s–1960s detached + apartments 1960s+ | North Sydney (3 km) |
| Cremorne Point2090 | $3.5M–$8.0M | 350–700m² | Class M (sandstone) / H–E (harbour fall) | 1900s–1940s heritage + 1960s+ apartments | North Sydney (4 km, ferry to Circular Quay) |
| Neutral Bay2089 | $2.5M–$4.0M | 300–550m² | Class M (sandstone ridges) / H to E (harbour fall) | 1900s–1940s + 1960s+ apartments | North Sydney (2 km) |
| Mosman2088 | $4.5M–$8.0M | 500–1,000m² | Class M (sandstone ridges) / H to E (harbour fall) | 1880s–1940s heritage | North Sydney (4 km, ferry from Mosman Bay) |
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?
Talk to our team — free site assessment and fixed-price quote.
How It Works
From First Call to Final Key
We assess your Cremorne home — existing structure, block size (350–600m²), R3 Medium / R4 / B4 mixed zoning, setbacks, FSR, and your space requirements. You'll know what's achievable before spending on detailed design.
⏱Design phase covers the extension layout, junction with existing structure, window and door placement, and external finish to match your Cremorne home's streetscape. Multiple design options presented.
⏱Documentation pack covers structural engineering for the new footings sized to match existing depths on Class M (sandstone ridges) / H to E (harbour fall) soil, BASIX 2025 compliance, shadow diagrams to neighbours' POS, hydraulic, and detailed sections through the wall-tie junction. Approval-grade, not concept-grade.
⏱Fixed-price construction of your extension. New footings engineered for Class M (sandstone ridges) / H to E (harbour fall) soil, structural connection to existing home, frame, fit-out, and finishes. Weekly updates from your project manager.
⏱Handover documentation covers the new work specifically — OC for the extension, structural certs, BASIX certificate updates, and warranty for the new section plus the junction detailing. Existing house remains under whatever warranty position applied before.
⏱Quality Promise
Buildana's Cremorne home extension process: assess the existing structure, design the addition, approve, build. Fixed price throughout.
Cost Guide
| Item | Estimated Range |
|---|---|
| Single-room addition (bedroom/study) | $77,000 – $180,000 |
| Kitchen/living extension | $190,000 – $450,000 |
| Master suite + ensuite addition | $170,000 – $360,000 |
| Second storey (full or partial) | $360,000 – $700,000 |
| Multi-room ground floor wrap | $450,000 – $770,000 |
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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Liverpool, NSW
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Last updated: 1 April 2026
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