What plans do I need for a room extension in SEQ?

Why plans are required for a room extension

A room extension is a building work that requires a building approval in Queensland. Under the Queensland Building Act, you cannot legally start construction without a building approval in place, and to get that approval, you need a set of drawings that shows exactly what you intend to build.

Your building certifier assesses the drawings against the relevant codes and standards, primarily the National Construction Code (NCC) and the applicable local planning scheme, and issues the building approval once satisfied.

Without approval ready drawings, you cannot get a building approval. Without a building approval, you cannot legally build.

What drawings are required for a room extension?

The specific documentation required varies based on the project, but a typical room extension approval in SEQ requires:

• 01
  Site planShowing the property boundaries, existing house footprint, the proposed extension location, setbacks to all boundaries and any easements or overlays.
• 02
  Floor planShowing the existing house layout and the proposed new room in context, dimensions, room layout, door and window locations, and how the new space connects to the existing dwelling.
• 03
  Roof planShowing how the new roof connects to the existing roof, drainage direction, and roof structure overview.
• 04
  ElevationsAll four external elevations of the combined existing house and new extension, showing materials, window locations and overall form.
• 05
  SectionsCut through drawings showing the structural relationship between the existing house and the new room, including wall, floor and ceiling heights.
• 06
  SpecificationA basic materials and construction specification covering the proposed construction method, materials and finishes.

Do you need existing house plans?

Yes, for room extensions, existing house plans are usually essential. Because the new room has to connect structurally and architecturally to the existing house, the drafter needs to understand the existing layout, roof form, wall construction and floor levels before they can properly document the extension.

If you don’t have existing plans, they’re often available from:

• ✓Your local council’s building records (usually available on request for a small fee)
• ✓The previous owner’s records if the home was built recently
• ✓A measured survey, where a drafter or surveyor visits the site and measures the existing house

We’ll advise on the best approach at suitability review based on your specific situation.

What else is involved beyond the drawings?

The drawings are the core of the approval application, but a room extension approval may also involve:

Structural engineering: Most room extensions require a structural engineer to certify the structural elements, beam spans, footings, connection to the existing structure. Engineering is separate to our fee and is arranged directly with a structural engineer.

Soil classification: Some certifiers require a soil classification report to specify footing requirements. This is typically a separate cost.

Planning scheme compliance: The extension must comply with the relevant local planning scheme, setbacks, site coverage, height and any overlay requirements. We check planning scheme compliance as part of the suitability review. Learn more about the room extension plans service.

Common questions