How the common terms differ
| Common name | Typical use | Questions to resolve |
|---|---|---|
| Granny flat / secondary dwelling | A self-contained residence with cooking, bathing, toilet and living facilities. | Is a second dwelling allowed, which approval pathway applies, and what size or siting standards must be met? |
| Backyard cabin | A broad product description that may refer to a retreat, guest space or small dwelling. | What building classification and approved use is included in the quoted product? |
| Garden studio / backyard office | Work, study, hobbies or recreation, often without full residential facilities. | Will it include plumbing, cooking or sleeping, and do those uses change the approvals? |
| Shed or workshop | Storage, tools, vehicles, making or agricultural uses. | Is it non-habitable, and are size, fire, boundary, access or business-use controls relevant? |
| Prefab or modular building | A construction method rather than a use; it can describe many of the above. | Who is responsible for site design, transport, foundations, connections and certification? |
If off-site construction suits your brief, explore the Australian prefab and modular home supplier directory to compare state coverage and project scope.
Six questions to ask before buying
- What is the approved use? Be explicit about sleeping, cooking, bathing, working, guests, family occupation or rent.
- What exactly does the price include? Ask about GST, delivery, foundations, site works, crane access, assembly, services, finishes, decks and approvals.
- Who is the responsible practitioner? Identify who designs for the site, obtains permits and certifies the completed work.
- Has access been checked? A prefab module may not reach a rear yard without cranes, temporary removal or a different construction method.
- What changes are allowed? Adding a bathroom or kitchen later may change the classification and require more work or approval.
- What evidence comes at handover? Request approvals, inspection records, certificates, warranties and final drawings.
Plan for comfort as well as compliance
Small detached rooms can overheat, lose heat and transmit noise quickly if orientation, shading, insulation, glazing, ventilation and materials are treated as afterthoughts. Consider daylight, glare, privacy, acoustic separation, step-free access, storage and the route between the building and the main home.
Find the right professional
A building designer or architect can translate the use into a brief; a planner can interpret site controls; a land surveyor records the site; an engineer designs structural elements; a building surveyor or certifier handles the relevant building approval role; and registered builders and licensed trades complete regulated work. The exact team depends on the jurisdiction and project.
Use the professional directory to compare service areas and project types, or follow the step-by-step granny flat checklist for a self-contained dwelling.
This guide is general information. Names, definitions and approval requirements vary across Australia and can change. Confirm the proposed use and current requirements with the relevant council or authority and qualified professionals.