Kellyville Home Extension Builder — Live In, Build On
Buildana extends homes across Kellyville 2155 while you stay in place. 1990s–2010s-era structure, The Hills Shire Council rules, weatherproofing during build — all managed locally from Fairfield.
HIA Member
MBA NSW0476 300 300Quick Answer
A home extension in Kellyville 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 Kellyville
A home extension in Kellyville reads the home's decade — the 1990s stock takes wings confidently and often benefits, while the 2010s homes get the honest are-you-sure conversation first.
The 500 to 800m² blocks hold rear additions and ground-floor suites, the clay junctions are engineered, and the Metro keeps the finished homes in deep demand.
At the $1.8M to $2.6M median, staying and extending beats the six-figure friction of upsizing in the corridor.
We build these fixed-price, licence HBL 487805C. Get our extension scope, with the era read, before you commit.
Buildana manages the complete home extension process in Kellyville — 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 Kellyville from $150K
- The Hills Shire Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- M — structural engineering included
- 1990s–2010s-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Kellyville (Sydney Metro Northwest, in suburb) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
The decade decides
Kellyville's 1990s homes are at the age extensions serve best — plans that predate open living, families that outgrew them — while the newer stock often needs a targeted wing or nothing yet.
I give the read before the design money moves.
Clay junctions engineered
The Wianamatta clay shifts through the seasons, so the new footings are tied to move with the original slab where they meet.
The engineering is drawn and priced before a slab is poured.
Home extension builder in Kellyville — key facts
- Suburb
- Kellyville, NSW 2155
- Council / LGA
- The Hills Shire Council (The Hills)
- Primary zoning
- R2 Low
- Typical lot size
- 500–800m²
- Soil class
- M
- Median house price
- $1.8M–$2.6M
- Home era
- 1990s–2010s
- 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.
How It Works
From First Call to Final Key
We assess your Kellyville home — existing structure, block size (500–800m²), R2 Low 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 Kellyville home's streetscape. Multiple design options presented.
⏱Documentation pack covers structural engineering for the new footings sized to match existing depths on Class M 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 soil, structural connection to existing home, frame, fit-out, and finishes.
⏱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 Kellyville home extension process: assess the existing structure, design the addition, approve, build. Fixed price throughout.
Cost Guide
| Item | Estimated Range |
|---|---|
| Adding a master suite (1990s–2010s Kellyville home) | $130,000 – $290,000 |
| Kitchen/living open-out to backyard | $150,000 – $360,000 |
| Second storey for teenagers/office | $290,000 – $560,000 |
| Extension + bathroom (growing family) | $200,000 – $410,000 |
| Full rear + roof tie-in (entertainer's zone) | $360,000 – $610,000 |
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
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
We Build Across Sydney
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
Extend, Don't Move — Kellyville
Free design consultation for Kellyville 2155. We'll assess your home, design the extension, and provide a fixed-price quote.
Start Your ProjectMore in Kellyville
Other Buildana services in Kellyville
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Kellyville 2155. The Hills Shire Council regulations and local controls are covered on each page.