Duplex and Dual Occupancy Drafting, Australia-Wide
Two homes on one lot can suit families, downsizers and investors. We check whether your site can take a duplex, then design and draw it for approval.
What we prepare
We start with a site check: zone, lot size and width, frontage, access, overlays and the local controls that decide whether a duplex is possible. If it is, we prepare concept options, then the full drawing set for planning and building approval, including site, floor, elevation, section, shadow and landscape plans where your council asks for them.
How the rules differ by state
- NSW. Dual occupancies are permissible with consent in R2 zones across most of the state since July 2024, and can use the Low Rise Housing Diversity Code where the council allows. See NSW.
- Victoria. Two or more dwellings need a planning permit, assessed under the Townhouse and Low-Rise Code. See Victoria.
- Queensland. Dual occupancy is controlled by each council's planning scheme. See Queensland.
- Western Australia. Assessed against the R-Codes and your density coding. See WA.
- South Australia. Your zone in the Planning and Design Code decides what is supported. See SA.
- Tasmania. Multiple dwellings under the Tasmanian Planning Scheme. See Tasmania.
- ACT. Rules for second homes in RZ1 and RZ2 are changing under the missing middle reforms. See ACT.
- Northern Territory. Most Zone LR land is limited to single dwellings. See NT.
Designing a duplex that works
A duplex has to work for two households and for the street. We look at the frontage and driveway layout, privacy between the homes and the neighbours, solar access, private open space and stormwater. Getting these right early avoids redesigns later. We recently drew a duplex in Derby WA, and the same careful site check applies to every lot. If you are in NSW, our duplex site check explains what we look at.
How the process works
- Send your address. Tell us what you'd like to do. We reply the same business day.
- Site and planning check. We look at the zone, the lot, overlays and your council's controls, and tell you the likely approval path.
- Concept design. Layout options, sized to the rules and your brief, that you can comment on before any detail is drawn.
- Drawings. The full set for planning and building approval, ready for your council, certifier or building surveyor.
- Lodgement support and coordination. We line up the surveyor, engineers and energy assessor, and help answer any questions that come back.
Get started
Send us your address and what you'd like to do. We'll check the zone, the lot and your council's controls, and come back with the likely approval path and a fee proposal. Every project is quoted on its own. We reply the same business day.
Granny flat plans · Duplex drafting · Knock-down rebuild plans · New home plans · Alterations and additions · How we work Australia-wide
Common questions
Can I build a duplex on my block?
It depends on your zone, lot size, frontage and local controls, which vary by state and council. We check your address and tell you whether a duplex is likely to be supported before you spend money on design.
What is the difference between a duplex and a dual occupancy?
They are mostly the same idea: two homes on one lot. Dual occupancy is the planning term in several states. They can be attached or detached.
Can a duplex be subdivided?
In many cases a duplex can later be subdivided or strata titled, but the rules differ by state and council. We check this as part of the site review.
Do you work on duplexes outside NSW?
Yes. We work Australia-wide with our own team in every state, including our duplex project in Derby WA.
Can you coordinate the engineers and surveyor?
Yes. We can coordinate the whole project, from survey and engineering to the energy assessment and lodgement.
What can you build on your block?
Send us the address and we’ll outline what your site can generally carry and the likely approval path. We reply the same business day.
Tell us about your project.
Send us your address and what you'd like to do. We'll check the zone, the lot and your council's controls, and come back with the likely approval path and a fee proposal. Every project is quoted on its own.
We reply the same business day.