External wall insulation in Wiltshire

The rules in England

Planning

On a house, external wall insulation is usually permitted development if the finish looks similar to the existing walls. Render or cladding on a house in a conservation area, National Park, National Landscape (AONB), the Broads or a World Heritage Site needs planning permission. Flats and maisonettes have no householder permitted development rights, listed buildings need listed building consent, and an Article 4 direction can remove rights locally.

Building regulations

Insulating more than half of a wall, or more than a quarter of the whole building envelope, counts as renovating a thermal element under the Building Regulations, so the wall should reach 0.30 W/m²K where that is technically, functionally and economically feasible, and building control must be involved.

Fire safety

On houses and other residential buildings up to 11m, Approved Document B sets surface rules only within 1m of a boundary. Residential buildings with a storey 11m or more above ground should have insulation of class A2-s1,d0 or better, and combustible materials are banned in the external walls of relevant buildings with a storey at least 18m up.

Funding

Low-income households in homes rated below EPC C can apply for Warm Homes: Local Grant where their council is taking part. The Great British Insulation Scheme closed on 31 March 2026, and ECO4 closes on 31 December 2026; its final months are for finishing and putting right existing work. Grant schemes use their own approved installers, so check a scheme's installer rules before booking; our quotes are for privately funded work unless we confirm otherwise in writing. Grants guide

VAT

Installing insulation in a home is zero-rated for VAT until 31 March 2027, then 5%.

Checked October 2026. Rules change, so we confirm them for your address at survey.