By QED Consulting Engineers — structural & civil engineers, Notting Hill, Melbourne
If you're extending your home, a structural engineer designs the parts that carry load — footings, beams and framing — and provides the drawings your builder and building surveyor need. For almost any extension that adds floor area or a second storey, engineering is part of the process.
Here's what an engineer does on an extension, when to engage one, and what you'll receive.
Do you need a structural engineer for an extension?
Yes, in nearly all cases. A ground-floor addition needs new footings and framing; a second-storey addition adds load to the existing structure below, which must be checked and often strengthened. Connecting new structure to old is one of the trickiest parts of any extension — and exactly where engineering matters most.
When should you engage the engineer?
Early — ideally during the design stage, alongside your architect or building designer. Bringing the engineer in early means the structure is coordinated with the design before you apply for a building permit, avoiding costly redesigns later.
What does the structural engineer design?
For a typical extension, the engineer designs:
- Footings and slab for the new section, suited to your soil
- Beams and lintels over openings and where walls are removed
- Framing for walls, floors and roof
- Connections between the new structure and the existing building
- Any strengthening of the existing structure to carry new loads
This is core work for our residential structural engineering team across Melbourne.
What you receive
You'll get structural drawings and computations — the documentation your building surveyor needs to issue the permit and your builder follows on site. A good engineer also stays available during construction to answer questions and resolve anything that comes up.
Planning an extension in Melbourne? Talk to a Melbourne structural engineer and we'll design it right from the start.
Frequently asked questions
Do I need a structural engineer for an extension? Almost always — extensions add structural loads, need new footings and framing, and must connect safely to the existing structure.
When should I engage the engineer? During the design stage, so the structure is coordinated before the permit application and before your builder starts.
What drawings does the engineer provide? Structural drawings and computations for footings, beams, framing and connections — the documentation needed for your building permit.
How does the engineer handle joining new to old? By assessing the existing structure and designing connections and any strengthening so the new and existing parts work together safely.
