If you are considering building a granny flat in Perth, one of the first questions is whether you need council approval. The good news is that in 2024, Western Australia made major changes to simplify the process and make it easier for homeowners to build.
Here’s everything you need to know about granny flat council approval in Perth, plus links to the official government sources so you can check the rules yourself.
The 2024 WA Granny Flat Reforms
In April 2024, WA updated the Residential Design Codes (R‑Codes) and removed many of the old barriers to building a granny flat. According to the WA Government media statement:
- The minimum lot size requirement of 350 m² was removed. You can now build on lots of any size, as long as you meet other standards.
- Granny flats up to 70 m² internal floor area that meet “deemed-to-comply” requirements no longer need planning approval.
- Parking requirements have been relaxed, with many sites no longer needing to provide an extra car bay.
These changes mean many homeowners can skip the lengthy planning approval process, saving time and money. It also means more property owners with smaller blocks can now take advantage of adding a granny flat as an investment or for multigenerational living.
When You Still Need Council Approval
Even with the new rules, there are times you’ll still need approval:
- If your design is larger than 70 m²
- If you don’t meet setback or open space requirements
- If you want to build outside the deemed-to-comply guidelines
If you fall into these categories, you’ll need to submit a development application to your local council. This adds time and cost but also ensures your project is legally compliant before you begin construction.
Building Permits are Still Required
Even if you don’t need planning approval, you still must obtain a building permit before construction can start. This step is crucial because it ensures your granny flat is structurally sound, energy-efficient, and compliant with the National Construction Code.
You can read more about building permit requirements on the WA Planning Commission site.
How Long Does Approval Take?
Planning approval, when needed, usually takes 6 weeks but can be longer depending on your council’s workload.
Building permits typically take 2–4 weeks after approvals are in place. If your project qualifies for an exemption, you can move straight to the building permit stage, cutting weeks off your timeline.
Costs Involved in Council Approval
Skipping planning approval can save you $2,500 to $7,500 in application and consultant fees. If you do need approval, budget for:
- Development application fee
- Building permit fee
- Site survey and engineering drawings
- BAL (Bushfire Attack Level) assessment if you’re in a bushfire zone
These costs can vary between councils, so always ask for an estimate up front.
How Council Approval Affects Your Budget
Understanding these requirements helps you plan a realistic budget. For example, if your block is narrow and doesn’t meet side setback requirements, you may need to modify your design or apply for a variation, which adds both design and approval costs.
By working with a builder who understands Perth granny flat regulations, you can minimise these variations and keep costs predictable.
Why Work with Experienced Builders
Partnering with experienced builders makes the process smoother. Phoenix Patios:
- Check your block and design against Perth granny flat regulations before quoting
- Manages all paperwork and council submissions
- Provides guidance on setbacks, privacy, and building code compliance
- Are experienced patio builders in Perth and offer carport installation in Perth, and Perth patio designs to complete your backyard upgrades.
This end-to-end service saves you from running back and forth between council offices, engineers, and trades.
Step-by-Step Approval Checklist
- Site Assessment: Measure block size, check zoning and services.
- Design Stage: Ensure plans meet deemed-to-comply standards.
- Council Review: Lodge development application if required.
- Building Permit: Submit construction drawings for approval.
- Construction: Begin building once the permit is granted.
- Final Inspection: Your builder will organise a final inspection to ensure the granny flat complies with your permit and regulations.
Smart Tip
If your block qualifies for the exemptions, you can start faster and reduce costs. Work with a builder who knows the rules and can confirm compliance upfront. You’ll not only save money but also get your granny flat ready to rent or use months sooner.
Get Expert Help with Your Granny Flat Project
Ready to get your granny flat underway without the stress? Phoenix Patios will check your design against current Perth granny flat regulations, handle council approvals when needed, and secure your building permit. Contact us today for a site assessment and a clear, upfront quote.
Frequently Asked Questions
No. Granny flats under 70 m² that meet deemed-to-comply provisions no longer need planning approval, though a building permit is still required.
Yes. Patios and carports may require a separate building permit and must comply with setback requirements.
Most modular granny flats take 12–16 weeks to construct once permits are in place. Site preparation, delivery, and installation are usually much quicker than a traditional extension.
Yes, once your build has final approval and meets all safety requirements, you can rent it out. Make sure you check any tenancy regulations and inform your insurer.