Home Extension Cattai — Design, Approval, Structural, Build
Full-service extensions in Cattai 2756: structural survey of existing Mixed rural home, design, The Hills Shire Council approval, engineering, weatherproofed construction, matched finish to original dwelling.
HIA Member
MBA NSW0476 300 300Quick Answer
A home extension in Cattai costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, The Hills Shire Council approvals, and construction under one fixed-price contract.
Second-Storey & Rear Additions in Cattai
A home extension in Cattai works at rural scale — two to ten-plus hectares along the Hawkesbury where the addition is sited to the land: pavilion wings, guest quarters, entertaining domains.
The mixed rural stock is read building by building, flood mapping is checked on the river-side land, and BAL ratings shape the external materials on the vegetated lots.
At the $2.5M to $6M+ acreage market, the extension protects a landholding that rarely comes up again.
We build these fixed-price, licence HBL 487805C. Walk us over the land and we will show you where the wing wants to sit.
Buildana manages the complete home extension process in Cattai — 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 Cattai from $150K
- The Hills Shire Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- M — structural engineering included
- Mixed rural-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near No rail (rural) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Sited to the land
Cattai's acreage frees the extension from suburban constraints — the wing sits where the land wants it, scaled to the holding rather than a boundary.
The mixed rural stock means every existing structure is assessed before the addition ties in.
River and bush conditions mapped
Flood mapping is checked on the Hawkesbury-side land and sets levels where it applies. BAL ratings shape materials on the vegetated lots, and rural services are scoped with the build.
All of it is mapped into the price before we start, not billed as it surfaces.
Home extension builder in Cattai — key facts
- Suburb
- Cattai, NSW 2756
- Council / LGA
- The Hills Shire Council (The Hills)
- Primary zoning
- R2 Low
- Typical lot size
- 2–10ha+ (acreage)
- Soil class
- M
- Median house price
- $2.5M–$6M+ (acreage)
- Home era
- Mixed rural
- 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) | $95,000 – $210,000 |
| Moderate extension (multiple openings, roof extended) | $210,000 – $400,000 |
| Complex extension (structural steel portals, re-roofing) | $400,000 – $630,000 |
| Second-storey tie-in (existing house re-engineered) | $370,000 – $680,000 |
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. Cattai homes from the Mixed rural 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
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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.
Extend, Don't Move — Cattai
Free design consultation for Cattai 2756. We'll assess your home, design the extension, and provide a fixed-price quote.
Start Your ProjectMore in Cattai
Other Buildana services in Cattai
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Cattai 2756. The Hills Shire Council regulations and local controls are covered on each page.