Granny Flat Builder Hornsby — From $150K Fixed Price
Fixed-price granny flat construction in Hornsby 2077. 1-bed from $150K, 2-bed from $185K. CDC approval, Hornsby Shire Council compliant. No hidden extras.
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MBA NSW0476 300 300Quick Answer
A granny flat in Hornsby costs $150,000–$300,000+ depending on size and finishes. 1-bed from $150K, 2-bed from $200K. CDC fast-track approval in 10–15 business days. Buildana manages design, Hornsby Shire Council approval and fixed-price construction.
Hornsby Granny Flat Construction — Fixed Price
Hornsby is the CBD and rail hub of the shire, so a granny flat here depends on which part you're in. Around the station it's R3 and R4 high-rise land — wrong place for a detached second dwelling. On the R2 residential streets, on generous 600 to 900m² blocks, it works well, and the station, Westfield and Hornsby Hospital give it a genuine rental market.
The blocks out here are generous, so space rarely limits you. The real work is the Hawkesbury Sandstone, which means rock excavation, and the bushfire ratings on the bushland-fringe streets — both common across the shire.
The sandstone commonly adds $30,000 to $120,000 for rock excavation, and where a block backs onto bushland there's a BAL rating to design for. I get a geotech and check the bushfire mapping before quoting.
Fixed price with the zoning, rock and bushfire all sorted first. Licence HBL 487805C.
Buildana manages the full granny flat process in Hornsby — from site assessment and CDC fast-track approval through to fixed-price construction and handover. We build studio, 1-bedroom, and 2-bedroom designs up to the NSW maximum of 60m².
Read our Complete Granny Flat Guide or explore granny flat builds across Sydney.
- Granny flats in Hornsby from $150K
- CDC fast-track approval (10–15 business days)
- 700–1,200m² typical (Hornsby/Asquith/Pennant Hills/Beecroft/Wahroonga boundary/Cherrybrook); 1–5ha acreage (Galston/Berrilee/Arcadia/Forest Glen/Glenorie/Berowra Heights bushland fringe) blocks — most qualify for 60m² granny flat
- Hornsby zoned R2 / R3 / R4 mixed (Hornsby CBD)
- Fixed-price contract — design to handover
- Hawkesbury Sandstone bedrock — engineered slab included
- Rental yield $520–$720/week (Hornsby Hospital + Hornsby TAFE + Macquarie University proximity) in Hornsby
- Free site assessment — near Hornsby station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Zoning sorts it first
Hornsby's CBD is high-rise apartment land, and a granny flat on R3 or R4 there is the wrong tool — that land earns more redeveloped. On the R2 residential streets a second dwelling is exactly right, and with the station, Westfield and the hospital close, the rental demand is real.
On generous 600 to 900m² blocks there's plenty of room to build a proper one or two-bedroom flat with its own yard.
Sandstone rock and bushfire
The Hawkesbury Sandstone means rock excavation is common — usually $30,000 to $120,000 above a standard substructure — so I get a geotech bore and put the rock in the fixed price rather than hitting it mid-build.
Where a block backs onto bushland, there's a BAL rating to design for. I check the mapping upfront so the build is set up for it. A tidy flat here lets steadily off the station, though I won't quote a weekly figure I can't back.
Granny flat builder in Hornsby — key facts
- Suburb
- Hornsby, NSW 2077
- Council / LGA
- Hornsby Shire Council (Hornsby Shire)
- Primary zoning
- R2
- Typical lot size
- 700–1,200m² typical (Hornsby/Asquith/Pennant Hills/Beecroft/Wahroonga boundary/Cherrybrook); 1–5ha acreage (Galston/Berrilee/Arcadia/Forest Glen/Glenorie/Berowra Heights bushland fringe)
- Soil class
- Hawkesbury Sandstone bedrock
- Median house price
- $1.8M–$2.6M Hornsby/Asquith/Mount Colah; $2.4M–$3.6M Cherrybrook/Beecroft/Pennant Hills; $3.0M–$8.0M+ Galston/Arcadia acreage
- Home era
- 1900s–1940s Federation heritage
- Typical price range
- $150,000 – $300,000+
- Typical timeline
- 4–6 months design to handover
- Approval pathway
- CDC via NSW Affordable Rental Housing SEPP (10–15 days)
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 |
|---|---|
| Attached granny flat | $160,000 – $220,000 |
| Detached granny flat | $190,000 – $260,000 |
| Above-garage granny flat | $230,000 – $300,000 |
| Premium detached (upgraded finishes) | $260,000 – $320,000 |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
How It Works
From First Call to Final Key
Assessment is the most important hour you'll spend on the project. Get the position, orientation, and access right and the build runs clean. Get them wrong and you're chasing certifier RFIs for months. Buildana checks every constraint before recommending a position.
⏱We design your granny flat to maximise the 60m² allowance within Hornsby Shire Council's setback and POS requirements. Floor plan, elevations, and 3D render provided. Studio, 1-bed, or 2-bed configurations available.
⏱CDC pathway exists specifically for compliant granny flats — use it. No neighbour notification, no Hornsby Shire Council planner queue, no committee politics. Certifier checks the design against the code; if it complies, it approves. 10–15 business days, every time.
⏱Fixed-price build: slab (Class Hawkesbury Sandstone bedrock engineered), frame, roof, fit-out, connections. 10–16 weeks depending on size. Minimal disruption to your existing home.
⏱Walk through your finished granny flat, collect keys. Occupation Certificate, 6-year structural warranty, and maintenance guide provided. List for rent immediately — typical demand in Hornsby fills vacancies fast.
⏱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 July 2025
Hornsby Granny Flat — Free Site Check
Free site assessment for Hornsby 2077. We'll check your block, recommend the best design, and provide a fixed-price quote.
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Other Buildana services in Hornsby
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Hornsby 2077. Hornsby Shire Council regulations and local controls are covered on each page.