Artist's impressionWhere we build
Duplex builders in the Hills District
A custom home in delivery near Tallawong metro, and a free written site assessment on your Hills block within two business days.
the Hills District
Building a duplex in the Hills District
Outside the State's mapped areas, a dual occupancy in R2 or R3 in The Hills needs 600 square metres for an attached pair and 700 square metres for a detached pair. The general dual occupancy controls do not set one council-wide frontage minimum for a DA, and precinct-specific controls may apply, so frontage is checked against the pathway and the precinct for each address.
The State's Low and Mid-Rise Housing Policy names Baulkham Hills, Bella Vista, Castle Hill, Hills Showground, Kellyville, Norwest and Winston Hills Mall. On eligible land within 800 metres' walk of one of those, 450 square metres and 12 metres of width may satisfy the State's duplex DA standards. Bushfire prone land is excluded from the State policy, so a block near a nominated station can still fall back to the council's 600 and 700 square metre numbers.
Complying development needs the council minimum for the duplex type and normally 15 metres at the building line, or 12 metres with qualifying rear or secondary access. The council's average DA assessment time was 115 days in the NSW council league table for June 2026, the slowest of the councils on this site, which makes the approval pathway worth settling early. Our custom home near Tallawong metro is just over the boundary in Blacktown.
Suburbs we cover include Castle Hill, Baulkham Hills, Kellyville, Bella Vista, Norwest, Winston Hills, Beaumont Hills, North Kellyville, Rouse Hill, Box Hill, Glenhaven, Cherrybrook, West Pennant Hills and Dural.
At a glance
- Where duplexes are permitted
- With consent in R2 and R3
- Council minimum lot
- 600 square metres attached, 700 square metres detached
- Frontage
- No single council-wide DA minimum; precinct-specific controls may apply
- Low and Mid-Rise Housing areas
- Within 800 metres' walk of Baulkham Hills, Bella Vista, Castle Hill, Hills Showground, Kellyville, Norwest or Winston Hills Mall. On eligible land, 450 square metres and 12 metres may satisfy the State's duplex DA standards
- Complying development
- At least 600 (attached) or 700 (detached) square metres and normally 15 metres at the building line, or 12 metres where parking is reached only from a secondary road, parallel road or lane
- Two titles
- A separate approval from building the two homes. We check Torrens or strata for your address
- Council assessment time
- Average 115 days, NSW council league table, June 2026
The State rules
How the State rules sit beside the council's
The rules come in layers, and they are easy to mix up. The first question is whether a duplex is permitted at all. Since 1 July 2024 dual occupancies have been permitted with consent in the R2 zone across NSW, and a council's LEP can permit them in other zones. That settles the land use only. It does not mean a particular block is big enough, wide enough or free of constraints.
Outside the State's mapped areas, the council's own minimum lot size and frontage apply to a development application. Since February 2025 the State's Low and Mid-Rise Housing Policy has added a second test. On eligible land within 800 metres' walking distance of a nominated station entrance or the mapped edge of a nominated town centre, a council cannot refuse a duplex DA for lot size or width if the block is at least 450 square metres and 12 metres wide at the front building line, with a floor space ratio up to 0.65:1, a height up to 9.5 metres and one parking space per home. The rest of the controls and the merits of the design still apply, so it is not automatic approval. The walk is measured along a safe public route, so the policy never covers a whole suburb. It does not apply inside transport oriented development areas, or on excluded land such as bushfire prone land, specified high-risk flood land, heritage items, high aircraft-noise land, coastal wetland and vulnerability areas, and land within 200 metres of specified dangerous-goods pipelines.
Complying development is a separate test again. Under the Low-Rise Housing Diversity Code the lot must be at least 400 square metres or the council's own duplex minimum, whichever is greater, and normally 15 metres wide at the building line, or 12 metres where parking is reached only from a secondary road, parallel road or lane. A block can fail complying development and still suit a DA, or meet the State's DA standards without qualifying for complying development. Separate titles are a separate approval as well.
Custom homes too
Not every block wants a duplex
The same site assessment tells you whether a single custom home or a knock down rebuild is the better use of the block. We build both, and we would rather say so early than push a duplex onto a site that suits one good home.
Projects nearby
Work in the Hills District
Our custom home near Tallawong metro is in delivery, just over the Blacktown boundary. The Nirimba Fields home is nearby.
How it runs
How a project runs
Test the site
Planning, frontage, access, services and the likely approval path, checked before design is fixed.
Set the brief and budget
Agree what matters, where to spend and what the project needs to achieve.
Design and price together
Architecture, engineering, selections and trade pricing move together, so the price is known before the contract.
Build from a settled scope
One program and one site team, with a weekly update and variations priced and signed before the work.
Common questions about duplexes in the Hills District
Can I subdivide a duplex in the Hills?
Subdivision is a separate approval from building the two homes, and the answer depends on the lot and the controls that apply to it. We check it for your address before the design starts, rather than assume either way.
What block size do I need in Castle Hill or Baulkham Hills?
600 square metres for an attached duplex and 700 square metres for a detached pair under the council's controls. On eligible land within 800 metres' walk of a nominated centre, 450 square metres and 12 metres may satisfy the State's DA standards instead.
Does the State 450 square metre rule apply around Rouse Hill?
Rouse Hill is not on The Hills list of nominated centres, which is Baulkham Hills, Bella Vista, Castle Hill, Hills Showground, Kellyville, Norwest and Winston Hills Mall. The standard applies only on eligible land within 800 metres' walk of those, so we check the mapping for your address.
My block backs onto bushland. Does that matter?
Yes. Bushfire prone land is excluded from the State policy, so the council's numbers apply, and the design carries a bushfire assessment that can affect materials and cost. We check the bushfire map for your address first.
Planning facts on this page were checked on 29 September 2026 against The Hills Local Environmental Plan 2019, The Hills DCP, the Housing SEPP, the Codes SEPP and the NSW Low and Mid-Rise Housing Policy. They are a guide, not a guarantee for any property. Controls change and exclusions apply, so we confirm them for your address as part of the free site assessment. This page is general information, not planning advice or an approval.
Tell us the address of your block in the Hills District.
Send the address and what you want to build. Within two business days you will have a written site assessment and a clear next step.