Home Extension Builder Spit Junction — Approved in 60 Days
Spit Junction 2088 extensions with tight approval timelines. CDC where eligible (~15 days), DA via Mosman Council in 40–60 days. Construction 12–24 weeks depending on scope.
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MBA NSW0476 300 300Quick Answer
A home extension in Spit Junction costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Mosman Council approvals, and construction under one fixed-price contract.
Spit Junction Home Extensions & Additions
A home extension in Spit Junction turns on which side of Military Road you sit. Along the spine the B4 and R3 zoning carries development value that a wing spend genuinely has to be weighed against — on some of those blocks the land is the asset, not the house. Step onto the heritage side streets, though, and the calculation is simple: extend behind the character with confidence.
The Federation and inter-war stock on those quieter streets takes a designed-to-the-metre wing behind the conserved frontage, with Mosman's amenity still on foot. Pre-war fabric gets licensed treatment for its lead and asbestos, and the sandstone is read wherever the structure changes.
At a $3.5M to $5.5M median, an addition on the side streets is the natural play — provided you have checked the zoning first rather than after.
We build these fixed-price, licence HBL 487805C. Get our extension scope, with the zoning checked, before you commit.
Buildana manages the complete home extension process in Spit Junction — 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 Spit Junction from $150K
- Mosman Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- M — structural engineering included
- 1900s–1960s + apartments-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near North Sydney (5 km) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Spine or side street
Near Military Road the zoning value is checked before any wing — while the heritage side streets extend confidently: conserved frontage, a designed-to-the-metre addition behind, Mosman's amenity on foot.
An honest read of where your block sits decides the spend.
Fabric and ground handled
On the pre-war stock lead paint and asbestos are cleared under licence together, done properly.
The sandstone is read wherever the structure changes, and all of it is priced into the job from the outset.
Home extension builder in Spit Junction — key facts
- Suburb
- Spit Junction, NSW 2088
- Council / LGA
- Mosman Council (Mosman)
- Primary zoning
- R3
- Typical lot size
- 350–700m²
- Soil class
- M
- Median house price
- $3.5M–$5.5M
- Home era
- 1900s–1960s + apartments
- 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
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 |
|---|---|
| Single-room addition (bedroom/study) | $75,000 – $180,000 |
| Kitchen/living extension | $190,000 – $440,000 |
| Master suite + ensuite addition | $160,000 – $350,000 |
| Second storey (full or partial) | $350,000 – $690,000 |
| Multi-room ground floor wrap | $440,000 – $750,000 |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
How It Works
From First Call to Final Key
On-site assessment of your 1900s–1960s + apartments-era home in Spit Junction. We check structural condition, block dimensions (350–700m²), setback availability, and Mosman Council's DCP requirements. Written feasibility and cost estimate provided.
⏱Designing an extension is half about the new space and half about how it joins the old one. Doorway position, ceiling height transition, floor level matching, light wells — the junction makes or breaks how the finished home feels.
⏱We lodge your extension approval — CDC for eligible designs or DA through Mosman Council. Full documentation including structural engineering for Class M soil, BASIX, and shadow diagrams. CC issued before works start.
⏱For ground-floor rear extensions you usually stay in the house during the build, with temporary weatherproofing at the junction wall until the new section is locked up. Second-storey additions need a 4–8 week relocation during the roof-off and frame-up phase.
⏱Final inspection, Occupation Certificate, 6-year structural warranty. Your Spit Junction home now has the space your family needs.
⏱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
Spit Junction Extension — Free Consultation
Free design consultation for Spit Junction 2088. We'll assess your home, design the extension, and provide a fixed-price quote.
Start Your ProjectMore in Spit Junction
Other Buildana services in Spit Junction
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Spit Junction 2088. Mosman Council regulations and local controls are covered on each page.