Home Extension Builder Mortdale — From $150K Fixed Price
Fixed-price home extensions in Mortdale 2223. Rear extension $150K–$300K, second storey $300K–$500K. Georges River Council approvals managed. Free site consult.
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MBA NSW0476 300 300Quick Answer
A home extension in Mortdale costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Georges River Council approvals, and construction under one fixed-price contract.
Mortdale Home Extensions — Fixed Price
A home extension in Mortdale grows the established St George home — heritage and brick-veneer stock on 400 to 700m² blocks where the wing adds the family space and the rail keeps the commute a walk.
The pre-war fabric gets licensed handling, the reactive pockets get engineered junctions, and the R3 near the station gets the zoning check.
At the $1.5M to $2.4M typical, the wing wins over the friction of upsizing in the district.
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 Mortdale — 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 Mortdale from $150K
- Georges River Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- M — structural engineering included
- 1920s–1960s heritage Federation/Californian Bungalow + 1960s–1990s brick veneer + 2010s+ R3/R4 redevelopment around Hurstville/Kogarah/Beverly Hills CBDs-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Mortdale station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
The station stays in the plan
Mortdale's rail walk is the asset extending keeps — the wing adds the bedrooms and living while the commute stays effortless.
Near the station, the R3 value gets the check before any big spend.
Fabric and ground handled
On the pre-war fabric lead paint joins asbestos, and the reactive pockets get engineered junctions.
Both sit in the quote from the outset.
Home extension builder in Mortdale — key facts
- Suburb
- Mortdale, NSW 2223
- Council / LGA
- Georges River Council (Georges River Council)
- Primary zoning
- R2 Low Density
- Typical lot size
- 400–700m² typical (Hurstville/Kogarah/Beverly Hills/Penshurst/Mortdale/Carlton/Kingsgrove/Allawah); 600–1,200m² premium foreshore (Oatley/Lugarno/Peakhurst Heights/Connells Point)
- Soil class
- M
- Median house price
- $1.5M–$2.4M typical; $2.0M–$3.5M Oatley/Lugarno/Peakhurst Heights premium foreshore; $3.0M–$8.0M+ direct waterfront
- Home era
- 1920s–1960s heritage Federation/Californian Bungalow + 1960s–1990s brick veneer + 2010s+ R3/R4 redevelopment around Hurstville/Kogarah/Beverly Hills CBDs
- 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 |
|---|---|
| Simple rear extension (single wall removal, no roof change) | $90,000 – $200,000 |
| Moderate extension (multiple openings, roof extended) | $200,000 – $380,000 |
| Complex extension (structural steel portals, re-roofing) | $380,000 – $600,000 |
| Second-storey tie-in (existing house re-engineered) | $350,000 – $650,000 |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
How It Works
From First Call to Final Key
The first job on an extension is finding out what you're extending onto. Mortdale homes from the 1920s–1960s heritage Federation/Californian Bungalow + 1960s–1990s brick veneer + 2010s+ R3/R4 redevelopment around Hurstville/Kogarah/Beverly Hills CBDs 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.
⏱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
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Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Mortdale 2223. Georges River Council regulations and local controls are covered on each page.