Your Guide to Building a Granny Flat

We know that when it comes to building a sizable project like a granny flat – that requires a big financial commitment, energy and time – naturally you’ll have many questions; this is why we have created a step-by-step mini guide to help you assess your project and get started in no time.

1. Check Your Property’s Eligibility

Before you start dreaming up designs, make sure your property meets WA’s granny flat requirements:

  • Your block must be at least 450m².
  • The granny flat must be no larger than 70m².
  • It must comply with setback and height restrictions.

2. Design a Space That Works for You

Think about how you’ll use your granny flat. Will it be a rental property, a home office, or a quiet retreat for family? Key features to consider:

  • Open-plan living areas for a spacious feel.
  • The granny flat must be no larger than 70m².
  • It must comply with setback and height restrictions.

3. Budget Smartly

The cost of building a granny flat in Perth typically ranges from 80,000 to 150,000. Our top tips on how to keep costs under control:

  • Choose cost-effective materials without compromising quality.
  • Plan for unexpected expenses with a 10% buffer.

4. Navigate Approvals and Permits

The good news? Most granny flats in Perth don’t need council approval. However, you’ll still need:

  • A building permit to ensure compliance with safety standards.
  • The granny flat must be no larger than 70m².

5. Choose the Right Builder

Your granny flat is only as good as the team behind it. Look for:

  • Builders with experience in granny flat construction.
  • Positive reviews and a solid portfolio of completed projects.
  • Clear contracts with detailed timelines and costs.
building plans, power tools, and hardware fixings on a wooden table
a person relaxing in a hammock with a dog looking at them

6. Maximise Your Investment

Once your granny flat is built, make it work for you:

  • Rent it out to long-term tenants or list it on Airbnb or Bookings.com.
  • Use it as a home office or creative studio.
  • Enjoy the added space for family and guests.

Common Questions About Granny Flats

Do I need council approval to build a granny flat?

In most cases, no! Granny flats under 70m² are exempt from council approval in WA, provided they meet specific criteria.

How long does it take to build a granny flat?

On average, it takes 12-16 weeks from start to finish.

Can I build a granny flat on a small block?

Yes, as long as your block is at least 450m² and meets other zoning requirements.

Thank you! Well be in touch!
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