A granny flat can serve different purposes over its lifetime: space for a relative, a home office, or accommodation for someone outside the household. Those possibilities make it tempting to begin with a floor plan. A more useful starting point is a conversation about the site, the intended occupants and the decisions that will be difficult to change later. Asking questions before, during and after construction helps separate assumptions from agreed work, while leaving room for the unexpected conditions that building projects can reveal.

Before: establish what the site and brief can support

Start by describing how the dwelling is likely to be used now and how that might change. Will an occupant need a quiet entrance, step-free access or space for regular visitors? Is the priority privacy from the main house, a connection to the garden, or a balance of both? A builder can discuss design options, but the household needs to be clear about which compromises it would accept.

Ask what must be checked before the design is treated as feasible. In Australia, requirements can differ by location and by the circumstances of the property. Boundaries, access, existing services, easements, drainage and the position of the main home may all affect what can be built. Rather than assuming that a drawing represents an approved outcome, ask who will confirm the relevant planning and building requirements, what information they need, and when that confirmation will happen.

The quote deserves the same scrutiny as the layout. Ask which drawings and specifications it relies on, what is included, and what remains provisional or excluded. Site preparation, service connections, landscaping and work around the existing home can be easy to overlook in an early conversation. It is also worth asking what could cause the price or timetable to change and how those changes would be documented.

Questions to settle before signing

• Who is responsible for each approval, inspection and specialist assessment?
• How will access to the site work while the main home remains occupied?
• Which materials and finishes are specified, and where are selections still open?
• What is the process for requesting, pricing and approving a variation?

Answers are most useful when they can be checked against the written agreement. If a contract, approval condition or ownership arrangement is unclear, seek appropriately qualified advice before committing. A reassuring conversation is not a substitute for understanding what the documents actually say.

During: make decisions visible rather than hurried

Once work begins, the questions become more immediate. Ask who your day-to-day contact is, how often progress will be discussed, and how decisions that affect cost or timing will be recorded. A short, regular update can make it easier to distinguish routine sequencing from an issue that needs the owner’s input. It also gives everyone a chance to identify decisions needed soon, rather than making them under pressure on the day.

Living beside a building site brings practical concerns beyond the new dwelling itself. Discuss where deliveries will arrive, which areas of the property need to remain accessible, and whom to contact about an unexpected interruption. If children, pets or visitors use the yard, ask how work areas will be separated and how changes to access will be communicated. Leave site safety measures and restricted work to the people responsible for them; the owner’s role is to raise concerns, not to improvise a fix.

Changes deserve a pause, even when they sound small. Moving a doorway may affect furniture placement, electrical planning, finishes or the construction sequence. Before agreeing, ask for the reason, the alternatives and the effect on the agreed price and completion schedule. Keep the revised decision with the other project documents so that a later discussion does not depend on anyone’s memory.

This is also a useful point to revisit the original brief with a granny flat builder: does the space taking shape still provide the privacy, circulation and everyday usability the household discussed at the outset? Asking while choices are still being made is more constructive than discovering a mismatch at handover.

After: check the handover, not just the finish

As completion approaches, ask what needs to happen before the dwelling is ready to use. The answer may involve inspections, paperwork, connections, cleaning and a review of outstanding items. Requirements vary, so confirm which documents are relevant to the particular project and who is arranging them. A practical handover should also explain how to operate and care for installed fixtures and equipment without relying on guesswork.

Walk through the space with the agreed drawings and selections available. Note anything that appears incomplete or different from what was agreed, and ask how outstanding work will be recorded, addressed and confirmed as finished. A written list with clear responsibilities is easier to follow than a casual promise made while everyone is standing in the doorway.

Finally, ask what to do if an issue appears after the dwelling is occupied. Who should receive the report, what details would help them understand it, and where are the relevant product documents and project records kept? Keep copies of approvals, contracts, variations and handover material together. That paperwork may matter long after the tools have left the site.

The best questions change as a project moves forward. Before construction, they test whether the idea fits the property and the household. During construction, they keep decisions and disruptions manageable. Afterward, they help establish what has been delivered and what remains to be resolved. None requires the owner to become a building expert; each helps make the next conversation more precise.