Garden room planning permission, without the hand-waving
Most garden rooms fall under Permitted Development - but the limits are exact, and the popular summaries skip the awkward cases. These guides check real parametric designs against the actual thresholds, the same checks our configurator runs live while you design.
| Scenario | The rule that bites |
|---|---|
| 2 m+ from every boundary | 3 m overall on a flat roof - the comfortable path |
| Within 2 m of a boundary | 2.5 m total height cap - brutally tight for an insulated build |
| Over 15 m² / 30 m² internal | Building Regulations siting rules, then full approval |
Twenty Paces is a planning aid, not professional structural or planning advice. Costs are materials-only at indicative merchant rates (excluding labour and delivery); span tables, U-values and regulations thresholds are indicative. Verify your design with a structural engineer, your local planning authority and Building Control before you build.