Do you need planning permission for external wall insulation?
The short answer
On a house in England, EWI is usually permitted development if the finish looks similar to the existing walls. You need planning permission in conservation areas and other designated land, for flats and maisonettes, and if the appearance changes; listed buildings also need listed building consent. Wales adds a 16cm projection limit, and Scotland and Northern Ireland should be checked with the council.
England
Householder permitted development allows exterior work where the materials are of a similar appearance to the existing house. Changing from brick to render, or changing render type or colour, is likely to alter the appearance and need an application. In conservation areas, National Parks, National Landscapes (AONBs), the Broads and World Heritage Sites, cladding a house in render, stone, pebbledash, timber, plastic or tiles always needs planning permission. Flats and maisonettes have no householder permitted development rights. Article 4 directions can remove rights in particular streets.
Wales
Welsh Government guidance says cladding can usually go ahead without an application if the materials look similar to the house, but external wall insulation projecting more than 16cm from the wall needs planning permission, and so does any EWI in designated areas. Slim boards such as phenolic can help keep a project within the limit.
Scotland and Northern Ireland
Permitted development rules for external alterations are narrower, and we advise checking with the council's planning service before ordering. In Scotland, separately from planning, an external insulation cladding system normally needs a building warrant. In Northern Ireland, council building control approval is needed.
Listed buildings
In every UK nation, external changes to a listed building need listed building consent. Breathable options such as insulating lime render are more likely to be acceptable than board systems.
Related services
Questions people ask
Can I apply for a Lawful Development Certificate?
In England and Wales you can apply to confirm that work is permitted development. It is useful evidence when you sell.
Does brick slip avoid planning permission?
If it looks similar to the existing brick, it is more likely to count as similar appearance. Designated areas and flats still need permission.