What is the maximum size for a garden room?

The maximum size of a garden room depends on a few key factors, including roof span, panel efficiency, and intended use.

For roof span:

• A 147mm thick roof panel (cut at 606mm centres) can span up to 5.2m.

• A 172mm thick panel (also at 606mm centres) increases this span to 5.9m.

To maximise cost-efficiency, it’s best to design using full-size SIPs panels, which come in standard sizes of 2440mm x 1220mm or 3000mm x 1220mm. This reduces waste and fabrication costs.

Lastly, if the garden room will be used as living accommodation, a thicker panel is needed to meet required U-values for insulation—the thicker the panel, the better the insulation performance.

If your design exceeds these parameters above get in touch as we can offer structural engineering calculations.