Solid wall insulation · England
Solid wall insulation in Northamptonshire
Planning solid wall insulation anywhere in Northamptonshire? We cover towns including Northampton and Kettering, and check planning and building control for each address. For solid-walled homes in Northamptonshire, we check wall thickness and age first to confirm there's no cavity to fill.
- Free survey and fixed written price
- Guide price from £75 per m² + scaffold, 0% VAT
- Planning and building control checked for England
Free survey in Northamptonshire
Tell us the postcode and what you need.
What the job covers
- External insulation keeps room sizes and treats cold bridges well
- Both can be done in stages, elevation by elevation or room by room
- Solid walls can lose heat roughly twice as fast as an insulated cavity wall
- In England and Wales, Building Regulations apply when more than half of a wall is treated
- Breathable options for stone and lime-mortared walls
Before we quote in Northamptonshire
Housing in the East Midlands includes Victorian terraces in the towns and cities, plenty of inter-war semis and post-war council estates, some of them system-built.
Much of Northamptonshire sits in the lower wind-driven rain exposure bands, which keeps the choice of finishes wide — though hilltop, coastal and exposed gable walls can still need a tougher specification, so we check the actual site.
On solid-walled houses in Northamptonshire, the gable or the most weather-exposed wall is often the place to start.
- Nation
- England
- Region
- East Midlands
- Towns covered
- Northampton, Kettering, Corby, Wellingborough, Rushden, Daventry
- Guide price
- From £75 per m² + scaffold · 0% VAT
Planning and building control in England
For houses, external wall insulation and render are often permitted development where the finish looks similar to the existing walls. Planning permission is usually needed in conservation areas, National Parks, National Landscapes, the Broads and World Heritage Sites (where cladding a house in stone, artificial stone, pebble dash, render, timber, plastic or tiles isn't permitted development), for flats and maisonettes, for commercial buildings, under an Article 4 direction, or where the look changes noticeably. Listed buildings need listed building consent.
Renovating more than half of a wall's area — insulating it, or stripping and re-rendering it — or more than a quarter of the building's whole external envelope brings in the energy requirements of Part L, so building control needs to be involved and the wall should reach about 0.30 W/m²K where that's technically, functionally and economically feasible.
How can I tell if my walls are solid?
Measure the wall thickness at a window or door: about 225mm (9 inches) of brick usually means solid, while 260mm or more often means a cavity. On exposed brick, a pattern with bricks laid end-on (headers) every few courses points to solid construction. Stone walls are usually solid regardless of thickness. Age is a strong clue too — most homes built before the 1920s are solid-walled.
Solid wall insulation prices in Northamptonshire
| Item | Guide price | Notes |
|---|---|---|
| External (EWI) | £105–£210 per m²0% VAT | By board and finish |
| Internal (IWI) | £75–£130 per m²0% VAT | Plus making good |
| Survey and written recommendation | Free with a quote |
Confirmed by a fixed written quote after survey. 0% VAT: installing insulation in a home is zero-rated until 31 March 2027, so these figures are the total; 5% applies from 1 April 2027.
From enquiry to finished wall
Get a guide price
Try the online quote tool for a ballpark figure.
Book the survey
A visit at a time that suits you.
Agree the quote
Nothing starts until you've signed the written price.
We do the work
Planned around weather, with you kept informed.
Solid wall insulation in Northamptonshire: questions
Does solid wall insulation cause condensation?
It can if detailed poorly, particularly internally. A condensation risk check for the proposed build-up and careful detailing at joists, reveals and corners avoid it.
Can I do one wall at a time?
Yes. Many owners start with the coldest or most exposed elevation, often a gable end.
Can I get a grant for solid wall insulation?
Some schemes cover it for eligible households — for example ECO4 until 31 December 2026, Home Energy Scotland's grant and loan, Wales' Warm Homes Nest and NI's Affordable Warmth Scheme. Each has its own eligibility and installer rules; see our grants guide.
Do you cover all of Northamptonshire?
Yes. We survey and quote solid wall insulation across Northamptonshire, including Northampton, Kettering, Corby, Wellingborough, Rushden.
Do I need planning permission in England?
For houses, external wall insulation and render are often permitted development where the finish looks similar to the existing walls. We check your address before quoting.