Note: This article includes links to Granny Flats 4U digital products and planning resources.

A granny flat can be a useful way to create family accommodation, rental income or a more flexible backyard, but the first price you see online is rarely the full project picture. Before you spend serious money, it is worth checking a few practical items first.

1. Check whether the site is practical

The building design matters, but the property often decides how simple or difficult the project will be. Check backyard space, access, slope, trees, drainage, services and where delivery or craning might happen.

2. Look beyond the advertised building price

Budget for drafting, engineering, certification, site works, delivery, craning, electrical connection, plumbing, water, sewer or septic, stormwater and any site-specific reports. These items can change the real number quickly.

3. Watch for approval and risk flags

Queensland projects may need checks around overlays, bushfire/BAL, vegetation, koala habitat, flood, easements, stormwater and energy efficiency. The right pathway depends on the property and local requirements.

4. Run a rough ROI check early

If rental income is part of the reason, compare rent, finance, vacancy, maintenance and management costs before choosing a design. A quick cashflow check helps you decide whether the project is still worth investigating.

5. Compare suppliers with the same questions

Ask what is included, what is excluded, what drawings are supplied, what approvals are included, who handles engineering, what warranty applies and what extra site costs are likely. Comparing clear quotes is much easier than comparing vague headline prices.

If you want to stay lighter, the QLD Investor Starter Pack includes the guide, calculator and worksheets without the video lessons.