Insulated plasterboard
Plasterboard bonded to a rigid insulation board, fixed to the wall and finished with a skim coat. It performs well for its thickness and is quick to fit.
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Internal Wall Insulation for Solid-Wall Homes
Internal wall insulation lines the inside face of your outside walls, keeping more heat in rooms that have solid brick or stone walls with no cavity to fill.
2xthe heat lost through an uninsulated solid wall compared with a cavity wallSource: Energy Saving Trust
0.30 W/m²KU-value threshold for walls upgraded with internal or external insulationSource: Building Regulations Approved Document L
Loft & Insulation
Internal Wall Insulation with EcoBuild Contractors
Homes built before about the 1920s usually have solid walls: a single thick layer of brick or stone with no gap to fill. Solid walls lose heat much faster than insulated cavity walls, which is why rooms in Victorian and Edwardian houses can feel chilly even with the heating on. Internal wall insulation adds a layer of insulation to the inside face of those outside walls, finished with plaster so the room looks as it did before.
It is often the right choice when the front of the house cannot change, for example in a conservation area, on a period terrace with decorative brickwork, or where external insulation would cause problems at the boundary. Because the work is carried out room by room, you can insulate the coldest rooms first or tie it in with a redecoration you already have planned.
Insulating a solid wall from the inside changes how moisture moves through it, so the design has to be right. We check for existing damp, choose a system that suits the wall, and seal the warm side with a vapour control layer where the system needs one. We work in homes across Bedfordshire and nearby, and some eligible households may be able to get help with the cost through government schemes.
What we do
Internal wall insulation systems we install
Insulated stud walls
A timber or metal frame is fixed against the wall, filled with insulation and boarded. It suits uneven walls and leaves space to run cables.
Thermal lining
Thin thermal lining boards suit rooms where space is tight, giving a warmer wall surface with very little loss of floor area.
Window reveals and junctions
Thin high-performance boards go around window reveals and at wall junctions to reduce cold bridges, where condensation and mould tend to show first.
Vapour control and airtightness
A vapour control layer or sealed foil-backed board on the room side keeps warm, moist air away from the cold masonry behind the insulation.
Refitting fixtures
Skirting boards, window boards, radiators and sockets are taken off and refitted on the new wall face. Electrical work is carried out by competent, qualified electricians with certification provided where applicable.
Bay windows and single rooms
Draughty bays and individual cold rooms can be insulated on their own when a whole-house job is not practical.
Why it is worth it
Benefits of internal wall insulation
Rooms that warm up faster
The insulated surface heats up quickly when the heating comes on, so rooms reach a comfortable temperature sooner and hold it for longer.
No change outside
The outside of your home stays exactly as it is, which matters for period features and conservation areas.
Fewer cold spots
Properly detailed insulation raises the temperature of the wall surface, reducing the cold patches where black mould often starts.
One room at a time
The work can be phased to suit your budget and the way you use the house.
Condensation risk and vapour control layers
When you insulate a solid wall on the inside, the masonry behind the insulation becomes colder than it was. If warm, humid air from the room can reach that cold surface, it condenses inside the wall where you cannot see it. This hidden moisture, known as interstitial condensation, can lead to mould behind the boards and decay in timber joist ends built into the wall.
The usual answer is a vapour control layer on the warm side of the insulation, taped at joints and sealed around sockets and edges, or an insulated board with a foil facing that does the same job. On older walls laid in lime, a breathable system may be the safer option because it lets the wall dry out in both directions. Either way, good ventilation in the room still matters, especially in kitchens and bathrooms.
How much room space will I lose?
That depends on the system and the performance you need. Insulated plasterboard is the slimmest common option, while a stud wall with insulation takes up more depth but copes better with walls that are out of true. In a typical room the change shows on a tape measure but is rarely noticed once furniture is back in place.
Approved Document L of the Building Regulations sets a U-value of 0.30 W/m²K for walls being insulated, but it allows a lower standard where meeting it in full would not be technically, functionally or economically reasonable, for example where it would take too much space from a small room. We explain the options for each wall before work begins.
Our process
How the job runs
- Survey and moisture checkWe confirm the walls are solid, measure the rooms, and look for rising or penetrating damp that must be fixed before any insulation goes on.
- System designWe pick the insulation type and thickness for each wall, plan how to handle window reveals, floor junctions and joist ends, and agree what needs moving.
- InstallationFixtures are removed, the insulation and vapour control layer are fitted and sealed at every edge, and services are brought through to the new surface.
- FinishingThe walls are skimmed, skirting and window boards go back on, and the room is left clean and ready for decorating.
FAQ
Internal Wall Insulation questions
Do I have solid walls?
Measure the wall depth at a window or door reveal: below roughly 260mm, it is probably solid. Brickwork with alternating long and short brick faces is another clue, and our survey confirms it.
Can I stay at home while internal wall insulation is fitted?
Yes. We work on one room or a few rooms at a time and keep dust contained, though the rooms being worked on will be out of use for a few days.
Can I hang shelves, a TV or radiators on the insulated walls?
Yes, with the right fixings. Heavy items need fixings that reach the masonry or timber battens added during installation, so tell us beforehand where you plan to put them.
Is internal or external wall insulation better?
External insulation keeps all your room space and deals with cold bridges at floor level more easily, but it changes the look of the house and may need planning permission. Internal insulation leaves the outside untouched and can be done in stages.
Does internal wall insulation need Building Regulations approval?
In most cases, yes. Insulating an external wall counts as renovating a thermal element, so the work has to meet the energy efficiency rules and be notified to building control.
Free, no-obligation quote
Get a free quote for internal wall insulation
Tell us a little about your property and the work you need. Add a few photos if you can, it helps us give you an accurate price sooner.
Related services
Often booked with internal wall insulation
Cavity Wall Insulation
Empty cavity walls let heat straight out. We survey your walls for suitability, inject blown mineral wool from outside, then fill and match the drill holes.
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Mould Removal & Damp Treatment
Black mould removed, condensation and damp investigated, then ventilation, extractor fans, PIV and anti-mould coatings fitted so the problem stops coming back.
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Home Ventilation & PIV
Humidistat, continuous running and kitchen extractor fans plus loft-mounted Positive Input Ventilation, sized to Approved Document F to clear steam and stop condensation.
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