Killarney Heights Home Extension Builder — Live In, Build On
Buildana extends homes across Killarney Heights 2087 while you stay in place. 1960s–1980s-era structure, Northern Beaches Council rules, weatherproofing during build — all managed locally from Fairfield.
HIA Member
MBA NSW0476 300 300Quick Answer
A home extension in Killarney Heights costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Northern Beaches Council approvals, and construction under one fixed-price contract.
Second-Storey & Rear Additions in Killarney Heights
A home extension in Killarney Heights usually turns on the rock. These established bushland-fringe blocks of 600 to 900m² sit on Hawkesbury Sandstone where excavation runs $40K to $120K, so digging out for a ground-floor addition can cost more than building up, and up often claims a view across the Garigal bushland and Castlecrag fall. On a $2.2M to $3.4M street, the right level pays for itself.
Bushfire follows the bush. Lots backing Garigal National Park carry BAL-12.5 to BAL-29 ratings, and every new external element of an extension gets specified to match. The 1960s to 1980s brick homes generally carry a first-floor addition once an engineer confirms the footings on that solid rock base, and the generous blocks leave room for a rear addition where owners prefer to stay level.
What I would check first on your Killarney Heights block: where the sandstone starts under a dig, the BAL rating, and whether an upper level would claim a view. Those set the direction.
We build these fixed-price, licence HBL 487805C. Get a BAL-literate quote built on a test dig.
Buildana manages the complete home extension process in Killarney Heights — 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 Killarney Heights from $150K
- Northern Beaches Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Hawkesbury Sandstone — structural engineering included
- 1960s–1980s-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near B-Line bus to CBD (Forestville interchange) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
The rock decides
These bushland-fringe blocks of 600 to 900m² sit on Hawkesbury Sandstone where excavation runs $40K to $120K, so digging out can cost more than building up.
Up often claims a view across the Garigal bushland and Castlecrag fall, and on a $2.2M to $3.4M street the right level pays for itself.
Bushfire and big blocks
Lots backing Garigal National Park carry BAL-12.5 to BAL-29 ratings, and every new external element is specified to match.
The 1960s to 1980s brick homes generally carry a first-floor addition once footings are confirmed, and the generous blocks leave room for a rear addition where owners prefer to stay level.
Home extension builder in Killarney Heights — key facts
- Suburb
- Killarney Heights, NSW 2087
- Council / LGA
- Northern Beaches Council (Northern Beaches)
- Primary zoning
- R2 Low
- Typical lot size
- 600–900m²
- Soil class
- Hawkesbury Sandstone
- Median house price
- $2.2M–$3.4M
- Home era
- 1960s–1980s
- 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) | $101,000 – $220,000 |
| Moderate extension (multiple openings, roof extended) | $220,000 – $430,000 |
| Complex extension (structural steel portals, re-roofing) | $430,000 – $670,000 |
| Second-storey tie-in (existing house re-engineered) | $390,000 – $730,000 |
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. Killarney Heights homes from the 1960s–1980s 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
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
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Other Buildana services in Killarney Heights
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Killarney Heights 2087. Northern Beaches Council regulations and local controls are covered on each page.