The NSW government has introduced updates to duplex development regulations bringing significant changes that will impact homeowners, investors, and developers across the state. These changes will create more opportunities for homeowners and developers while boosting the housing supply and ensuring sustainable, community-focused development. It’s the right time to explore options for people who have been considering duplex development.
Let’s have a look at previous rules, what’s changed, how these updates affect the housing market and how you can benefit from these updates.
What’s Changed?
The NSW Government is implementing key reforms to increase housing options and enhance affordability. The changes specifically aimed at diversifying housing types and easing development processes across the state. Below are the major updates:
Duplex-Specific Changes:
- New Minimum Lot Width
The minimum lot width has now been set at 12 metres for duplex and semi-detached homes. This rule applies in 124 council areas across NSW, with some exceptions. - New Minimum Lot Size
A minimum lot size of 450 square meters is required for duplex developments. - R2 Zone Councils Must Allow Duplexes and Semis
Councils within the R2 zone must now allow duplexes and semi-detached homes as permissible developments. This change helps homeowners and developers to build duplexes in previously restricted zones. - Exempt Areas
There are some areas where the new rules do not apply such as the regions: Hawkesbury, Blue Mountains, Wollondilly, and Bathurst, where local councils have specific restrictions. - Potential New Dwelling Estimates
These changes could result in the construction of thousands of new dwellings, minimising pressure on housing demand and opening up opportunities for investors and developers in various regions across NSW.
Updated Requirements from Previous Rules (2024 Reforms Updated in 2025)
The 2025 reforms build upon previous changes introduced in 2024. Here’s a recap of how these updates modify or enhance the earlier rules:
- Lot Size and Width:
The new 12-metre rule for duplex development marks a clear shift from earlier regulations. Previously, lot width requirements were more restrictive in some areas, but this update makes it easier for developers to build duplexes in an extensive range of locations. - Dual Occupancy Approvals:
Dual occupancies are now permitted as complying development if they meet the specific standards. This streamlines the approval process, as homeowners and developers can move forward with their projects more quickly by meeting the set criteria. - Setbacks, Height Limits, and Parking:
Many of the setbacks, height restrictions, and minimum parking requirements introduced in 2024 have not changed. Developers and homeowners need to check local council guidelines to confirm these details. - LGAs Impacted Most by Changes:
Local government areas (LGAs) such as Hornsby and Ku-ring-gai saw the most significant changes due to the new inclusions. These areas will see increased potential for duplex developments, contributing to a more diverse housing stock in high-demand suburbs.
What Homeowners & Investors Need to Know in 2025
These new policies present exciting opportunities for those looking to invest in or develop property in 2025. Here’s what you need to know:
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Impact on Property Values
Particularly in regions where duplexes, multi-dwelling homes, and low-rise buildings were previously restricted, the relaxation of development limits and the introduction of new housing types are expected to increase property values.
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New Opportunities for Knockdown Rebuilds or Renting
This is the perfect time to consider a knockdown rebuild for homeowners looking to upgrade their properties. Creating a duplex or a semi-detached home could offer significant rental income or multi-generational living solutions.
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Council-Specific Variation Awareness
Not all councils are the same as some may apply their own variations to the rules, particularly regarding things like parking, height limits, or site-specific considerations. It’s essential to consult with local authorities or professional advisors to ensure compliance with local regulations.
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Professional Help Recommendation
These changes can be tricky to follow. It’s highly recommended that both homeowners and investors should get professional guidance when planning a duplex build or low-rise development under these new rules. Kurmond Homes is here to assist you every step of the way, ensuring your projects meet the new standards and are completed with the utmost care and attention to detail.
Previous Duplex Rules NSW
Duplexes and semi-detached homes have long featured in the mix of housing across Sydney, particularly in inner city areas, but many councils in more recent times have banned them.
The new legislation, the State Environmental Planning Policy (Housing) Amendment (Dual Occupancies and Semi-detached Dwellings) 2024, was enacted on 1 July 2024.
Under the new rules, councils will remain the primary assessor of development applications, but they will now be required to consider duplex houses.
Significantly, dual occupancy homes and semi-detached dwellings are now permissible in the R2 zones in Hornsby, Ku-ring-gai, and Warringah, where they were not previously permitted. Plus, dual occupancies are now allowed in the R2 Low Density Residential Zone in Liverpool LGA, where they were not previously accepted.
The Hawkesbury, Blue Mountains and Wollondilly local government areas are exempt from the changes because they face a higher risk from bushfires and floods. Bathurst has no suitable residential land, so it is also excluded.
Analysts estimate that the changes could lead to thousands of new dwellings, including:
- 34,000 in Hornsby
- 25,200 in Ku-ring-gai
- 30,000 in the Northern Beaches
- 23,000 in Liverpool.
What Are the Rules to Build a Duplex in NSW?
As we mentioned, the block width is the most significant change, but here is a reminder of some key requirements of the NSW Low Rise Housing Diversity Code.
- Applies to R1, R2, R3 and RU5 zones, with most residential lots in Sydney falling into these zones.
- Designs must meet the relevant design criteria in the Low Rise Housing Diversity Design Guide.
- Dual occupancies can be approved as a complying development if they meet certain standards.
- To meet duplex land size requirements in NSW, blocks must be at least 400 square metres or the minimum lot size stipulated by the council.
- Each must face a public road and cannot be located behind another dwelling except on a corner block.
- Each dwelling must have at least one off-street parking spot.
Be Among the First to Benefit
Kurmond Homes has in-depth expertise in these new NSW duplex laws and changes, ensuring you can confidently navigate your build. Whether you’re an investor looking to maximise returns or a homeowner considering a duplex for multi-generational living, we’re here to help you make the most of these new opportunities.
Visit our duplex designs via our website to explore our latest designs, and let’s bring your vision to life.
Call Kurmond Homes today for a FREE consultation to discuss your options!
