Planning and building rules in Scotland, Wales and NI

How do planning and building rules differ in Scotland, Wales and Northern Ireland?

Short answer

Each UK nation has its own planning and building rules. England has the larger home extension scheme; Wales does not and requires sprinklers in new homes; Scotland usually requires a building warrant before work starts; Northern Ireland’s councils handle both planning and building control. The Party Wall Act applies only in England and Wales.

England

Permitted development under the 2015 order, including the larger home extension prior approval route. Building control from the council or a registered building control approver.

Wales

Its own householder permitted development rules: single-storey rear extensions up to 4 m, and two-storey rear extensions where there is at least 10.5 m to the rear boundary, but no larger home extension route. Welsh building regulations require sprinklers in new homes, and most new buildings need sustainable drainage approval.

Scotland

Householder permitted development for extensions and dormers dates from 2012 (current guidance: Circular 1/2024): single-storey extensions can project 3 m (terraced) or 4 m (other houses) where within 1 m of a boundary, and dormers are allowed only on roof slopes facing a boundary at least 10 m away. A building warrant from the council is usually needed before an extension, loft or conversion starts, and a completion certificate is submitted at the end.

Northern Ireland

Householder permitted development under the 2015 order: rear extensions of 3 m (4 m detached), and dormers controlled by set-backs rather than a volume limit. Planning and building control are both handled by the 11 councils, and there is no party wall legislation.

Sources and further reading

This guide is general information, not legal or tax advice. Rules change and depend on your property; we confirm what applies to your project at the survey.