Yes, many Windsor properties may be suitable for a granny flat, but the approval pathway depends heavily on the individual address. Established blocks in Windsor are often around 500–800m², so many may exceed the 450m² minimum lot size generally required for a detached granny flat under complying development. NSW planning rules typically allow a secondary dwelling of up to 60m², unless another planning instrument permits a larger area. Windsor includes R2 Low Density Residential land, where secondary dwellings are permitted, although zoning varies across the suburb. Extra care is needed because parts of Windsor are affected by Hawkesbury-Nepean flood planning controls, while properties within or near the Thompson Square heritage conservation area may face additional heritage requirements and a different approval pathway.
Get inspiration from our recent granny flat projects across Windsor and surrounds — and see how we’ve turned different properties into practical new spaces.
Windsor offers a strong case for adding flexible accommodation to an established property. About 41.6% of occupied homes in Windsor were rented at the 2021 Census, compared with 32.6% across NSW, showing a substantial local rental market. The suburb is also home to Hawkesbury District Hospital, the region’s key medical facility, while Windsor and nearby Richmond operate as the Hawkesbury’s main health, retail, professional-service and employment hubs. For homeowners with a suitable block, this makes a granny flat useful for independent accommodation for parents or adult children, while retaining the option to generate separate rental income in the future. It is a practical way to gain more from an existing Windsor property without needing to move.
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The three things that shape a granny flat build in Windsor: the planning rules, the ground you’re building on, and what the market gives back.
Median house price in Windsor
Typical granny flat rent
Key local landmark
your block
nearest station
A granny flat in Windsor can be approved through a private certifier as complying development when the lot is 450m2 or larger, the secondary dwelling is no more than 60m2 (or 25% of the main house, whichever is less), and setbacks, height and landscaping meet Housing SEPP 2021 standards. This pathway typically takes 10 to 15 business days once documentation is complete. Because parts of Windsor sit in a heritage conservation area, some otherwise eligible blocks will need a DA instead, which we confirm at the property check stage. Blocks inside a flood planning area can still qualify, but floor levels and fill must meet the council's flood controls, which we check against the flood certificate before design.
Not meeting one complying development requirement does not rule a project out. Where a block in Windsor is under 450m2, sits in a heritage conservation area, or is affected by a flood planning control, a development application can be lodged with Hawkesbury City Council. Assessment times are longer than a CDC, but the council does approve secondary dwellings through this route.
Windsor is administered by Hawkesbury City Council and assessed under the Hawkesbury LEP 2012. The whole suburb falls within the one council area. Granny Flats X confirms the consent authority for your specific block during the initial property assessment.
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The things Windsor homeowners ask us most. Can’t find yours? Call us — we’ll give you a straight answer.
Usually 12-14 weeks from approval. We fast-track the council paperwork.
Yes. Most Windsor blocks support 60m² 2-bedroom layouts.
Yes, but we handle the entire approval process for you.
