Internal wall insulation · Hertfordshire
Internal wall insulation in Harpenden
Internal wall insulation in Harpenden: free survey, written specification and a fixed price, with the details that keep walls dry planned from the start. For terraced homes in Harpenden with attractive brick fronts, one approach is to insulate the front internally and the rear externally.
- Free survey in AL5 and nearby
- Guide price from £75 per m² 0% VAT
- Fixed written price before work starts
Free survey in Harpenden
Postcode, service and a phone number is all we need.
Included as standard
- Needs careful detailing at floor joists, reveals and corners
- Insulated plasterboard, stud wall or breathable systems
- Keeps the outside of the house exactly as it is
- Loses roughly 50–100mm per insulated wall
Before we quote in Harpenden
We cover Harpenden and nearby St Albans, Luton and Hemel Hempstead. Harpenden sits around 11 miles from Watford. 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.
We plan internal insulation in Harpenden homes room by room so you keep the rest of the house usable.
- Postcode district
- AL5
- County or area
- Hertfordshire
- Nation
- England
- Nearby
- St Albans, Luton, Hemel Hempstead, Welwyn Garden City
Approvals in England
Internal insulation rarely needs planning permission, but in England and Wales insulating or replastering more than half of a wall's area involves building control, and listed buildings need consent for internal changes that affect their character.
What are the risks with internal insulation?
Insulating inside makes the masonry colder, so moisture risk rises. Weak points are where floor joists bear into the wall, window reveals and corners. A condensation risk check for the build-up, a continuous vapour control layer where specified, and returning insulation into reveals deal with most of it.
Internal wall insulation prices in Harpenden
| Item | Guide price | Notes |
|---|---|---|
| Insulated plasterboard, supplied and skimmed | £75–£110 per m²0% VAT | |
| Insulated stud wall | £90–£130 per m²0% VAT | |
| Typical bedroom, one external wall | £1,795–£2,9950% VAT | Including making good |
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.
What happens next
Enquiry
Send your postcode and a few details.
Measured survey
Walls, damp, eaves, cills and services recorded.
Written price
A fixed price with the specification attached.
Work and handover
Installed, inspected and documents handed over.
Internal wall insulation in Harpenden: questions
What happens to my radiators and sockets?
They're taken off and refitted on the new wall face. Electrical work is done by a qualified electrician.
Is internal insulation cheaper than external?
Per m² usually yes, but the cost of moving fittings and redecorating narrows the gap on whole-house jobs.
Can I stay in the house?
Yes, but each room is out of use while it's worked on, typically 3–5 days.
Do you cover Harpenden?
Yes — we survey and quote internal wall insulation in Harpenden (AL5) and nearby St Albans, Luton and Hemel Hempstead, with a fixed written price before any work starts.