Non-traditional houses · England
Non-traditional and concrete house insulation in Hertfordshire
Planning non-traditional house insulation anywhere in Hertfordshire? We cover towns including Watford and Stevenage, and check planning and building control for each address. Where a home in Hertfordshire is system-built, the first job is confirming the construction type.
- Free survey and fixed written price
- Guide price from £120 per m² + scaffold, 0% VAT
- Planning and building control checked for England
Free survey in Hertfordshire
Tell us the postcode and what you need.
Included as standard
- Most system-built homes have thin, cold walls and no fillable cavity
- EWI improves comfort and can renew a tired concrete exterior
- The survey identifies the construction type before anything is specified
- EWI is not a structural repair for PRC houses designated defective
- Steel-framed BISF houses need care around the upper-storey cladding

Before we quote in Hertfordshire
The East of England has a mix of post-war estates, inter-war semis and older solid brick and flint cottages, with some system-built council homes on post-war estates.
Much of Hertfordshire 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.
Where one half of a pair in Hertfordshire is insulated and the other isn't, we detail the boundary so the neighbour can join later.
- Nation
- England
- Region
- East of England
- Towns covered
- Watford, Stevenage, Hemel Hempstead, St Albans, Welwyn Garden City, Cheshunt, Letchworth Garden City, Hatfield…
- Guide price
- From £120 per m² + scaffold · 0% VAT
Approvals 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.
Does EWI fix mortgage problems with PRC houses?
Not on its own. Some precast reinforced concrete (PRC) house types were designated defective, and many lenders want a certified structural repair before they will lend. Insulation and render over the outside is not that repair. Other types, such as Wimpey no-fines, are generally treated differently. If mortgageability matters, speak to your lender or a surveyor before booking any work.
Non-traditional and concrete house insulation prices in Hertfordshire
| Item | Guide price | Notes |
|---|---|---|
| EWI on concrete or steel-framed walls | £120–£180 per m²0% VAT | Includes extra preparation |
| Semi-detached, full house | £11,400–£21,2000% VAT | 80–100 m² of wall, including scaffold |
| Concrete repairs found at survey | Priced separately | Only where needed |
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.
How it works
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.
Non-traditional houses in Hertfordshire: questions
What if my neighbour isn't insulating?
We finish the system neatly at the boundary with a closing detail so the neighbouring house isn't affected and can be joined later.
Will EWI make my house mortgageable?
It can make a house more attractive and better insulated, but it does not replace a certified structural repair where a lender requires one. Ask your lender before relying on it.
Can you put EWI on a BISF house?
Yes, with care. The steel frame and upper-storey cladding need a system and fixing method designed for that construction, and the condition of the frame should be understood first.
Do you cover all of Hertfordshire?
Yes. We survey and quote non-traditional house insulation across Hertfordshire, including Watford, Stevenage, Hemel Hempstead, St Albans, Welwyn Garden City.
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.