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Steel-frame granny flats
Why we build granny flats from light-gauge steel, and how they compare with the alternatives.
Our granny flats are framed in G550 light-gauge steel with an AZ150 zinc-aluminium coating to AS 1397, the same grade of steel used in steel house frames across Australia. The frame is made with machine precision in a factory, then folded for transport and unfolded on your slab.
What steel gives you
- No termites. Steel framing can't be eaten by termites, a real issue in many Perth suburbs.
- Straight and stable. Steel doesn't warp, twist, shrink or rot, so walls stay straight and cracks in linings are less likely.
- Non-combustible frame. Steel doesn't burn. Bushfire-prone lots still need the right BAL construction, which we design for.
- Light and fast. A light frame can be made off site and lifted into place, which is what makes a one-to-two-day install possible.
How the options compare
| Our steel modular flats | Traditional site build | Transportable (delivered whole) | |
|---|---|---|---|
| Time working in your yard | Weeks | Months | Weeks |
| Who installs and finishes | Registered builder, fixed price | Registered builder | Varies; site works often extra |
| Access needed | Truck and crane | Works on tight sites | Truck and large crane |
| Frame | Steel | Usually timber or steel | Usually steel |
| Design freedom | Seven layouts, adjustable | Fully custom | Set modules |
| Disruption | Low | High | Low |
Compare the total price, not the box
A kit or module price is only part of the cost. Ask every supplier for a price that includes the slab, delivery, crane, sewer, water and power connections, the building permit and any development approval. Our fixed price includes all of that.
Common questions
Are steel granny flats hot in summer?
Heat comes through the roof, walls and windows, not the frame. Our flats have insulated walls and ceilings, double-glazed windows and a Colorbond roof, and we look at orientation and shading on your block.
Is a modular granny flat a 'real' building?
Yes. It sits on a slab or footings, needs a building permit like any granny flat, and is connected to your water, sewer and power. It is part of your property, not a caravan or a temporary structure.
See what fits in your backyard
Book a free site visit. A registered builder checks your block, access and services, then sends a fixed-price quote.