Solid wall insulation · Kent
Solid wall insulation in Sevenoaks
Homeowners and landlords in Sevenoaks can get a free survey and a fixed written quote for solid wall insulation, covering TN13 and the surrounding area. For solid-walled homes in Sevenoaks, we check wall thickness and age first to confirm there's no cavity to fill.
- Free survey in TN13 and nearby
- Guide price from £75 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Sevenoaks
Postcode, service and a phone number is all we need.
What you get
- Internal insulation suits single rooms or where the outside can't change
- Both can be done in stages, elevation by elevation or room by room
- Breathable options for stone and lime-mortared walls
- In England and Wales, Building Regulations apply when more than half of a wall is treated

Local considerations in Sevenoaks
As well as Sevenoaks itself, we quote in Tonbridge, Swanley and Tunbridge Wells. Sevenoaks sits around 14 miles from Maidstone. Homes across the South East range from inter-war semis and post-war estates, which are mostly cavity-walled, to older solid-walled cottages and Victorian town terraces.
Much of Kent 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 Sevenoaks, the gable or the most weather-exposed wall is often the place to start.
- Postcode district
- TN13
- County or area
- Kent
- Nation
- England
- Nearby
- Tonbridge, Swanley, Tunbridge Wells, Chislehurst
Approvals in England
For a house in Sevenoaks, external insulation or render is often permitted development if it looks similar to the existing walls; conservation areas, flats, commercial buildings and listed buildings need permission or consent, so we check your address first.
Insulating or re-rendering more than half of a wall's area brings in Part L of the Building Regulations, so building control is notified and the wall is upgraded to about 0.30 W/m²K where practical.
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 Sevenoaks
| 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
Tell us about the property
Use the quote tool or form, or call. Photos help.
Free survey
We measure, check the walls and confirm approvals.
Fixed written quote
System, details, access, exclusions and VAT in writing.
Installation
Scheduled for suitable weather, with a clear programme.
Solid wall insulation in Sevenoaks: 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.
Is solid wall insulation worth it?
For many solid-walled homes it's one of the biggest single improvements to comfort, because the walls are often the largest heat-loss area. Savings depend on the home and heating, so we don't promise a figure.
Do you cover Sevenoaks?
Yes — we survey and quote solid wall insulation in Sevenoaks (TN13) and nearby Tonbridge, Swanley and Tunbridge Wells, with a fixed written price before any work starts.