The most common sizing mistake isn't ordering a shed that's too big — it's ordering one that fits today's gear perfectly and next year's gear not at all. Here are the rules of thumb our design team uses every day.
Standard garage footprints
- Single garage: generally 3.5m × 6m (21 m²), sometimes 3m × 6m.
- Double garage: generally 6m × 6m (36 m²) — also the threshold above which most non-farm buildings need an accredited builder to install.
- Add a carport extension or lean-to for extra sheltered space without adding much to the cost.
Thinking in bays, spans and heights
Steel sheds are designed as a series of bays under a clear span. The span (width) sets what you can drive or park inside without posts in the way; bays set the length and where the doors go; and height decides what tips, lifts or stacks under the ridge. Our portal frame system runs up to 9.5 metres high with 30-metre clear spans and lengths beyond 200 metres for commercial work — and every dimension can be adjusted in 100mm increments, so you pay for the shed you need rather than the next size up.
Questions that decide the size
- What has to fit inside — now, and in five years? Utes grow canopies; farms grow implements.
- Do you need workbench or storage room around the vehicles, or just parking?
- What's the tallest thing that will ever come through the door? Height is the dimension people regret most.
- Will the roller doors go in the gable end or the side? That changes which dimension needs the bays.
Try it in 3D, or let us size it with you
The fastest way to get a feel for size is the 3D Shed Designer: change the span, length and height, add your options, and send it to us for a quote. Or tell us the site and we'll design it with you: every Tassie Sheds building is ShedSafe accredited and engineered for your block's wind loading, not a generic postcode.