Internal wall insulation (IWI) adds a new insulating layer to the inside of your home’s external walls, so less heat escapes and rooms feel warmer. It’s usually done by fixing insulated plasterboard (rigid boards), building a new stud wall filled with insulation, or applying an insulating plaster finish.
Energy Efficiency Measures
Internal Wall Insulation
What is internal wall insulation?
IWI is commonly used on solid-walled homes (often pre-1920) or anywhere cavity wall insulation isn’t suitable.
The insulation will reduce heat loss and energy use, which can lower heating bills and cut carbon emissions. It also helps tackle cold surfaces and draughts.
What to Expect
Rooms are out of use while work happens and you should expect dust and redecoration afterwards. Skirting boards, some door frames, sockets, radiators and other fittings are usually removed and refitted.
Some walls, such as in kitchens and bathrooms, can also be challenging due to pipework. There will be some lost space on internal walls (around 6-10cm) and window reveals and sills may be adjusted.
For a typical home, installation often takes around 3–5 days, depending on size and complexity. Larger homes or detailed joinery take longer.
Internal works usually don’t need planning permission, but listed buildings need consent.
Ventilation – Because insulation and airtightness will improve, we will assess ventilation in your home so moisture doesn’t build up, which may result in some upgrades being required (e.g. trickle vents in windows, new fans in bathrooms, etc) – these will be explained prior to any works commencing.
Benefits of having internal wall insulation
- Lower energy usage – insulation helps prevent heat loss in the winter and heat gain in the summer, leading to lower heating and cooling costs.
- Warmer, more comfortable rooms with fewer cold spots and reduced draughts.
- Can help prevent condensation on internal wall surfaces.
- No change to the outside look of your home — ideal in conservation areas or where you want to keep the appearance unchanged.
- Can provide some sound resistance improvement and make rooms feel quieter.
- Cuts carbon emissions by reducing the energy needed to heat your home.
Energy Savings
Energy Bill Savings (£/year)
Here’s how much you could save on your energy bill (£/year) each year with internal wall insulation.
Sustainable Building Services: Energy efficiency measures you can trust
Sustainable Building Services (UK) Ltd is one of the UK’s leading installers of energy efficiency measures.
All measures are installed to the highest quality and Government standards.
They are installed to meet current Building Regulations for England & Wales.
An independent guarantee is provided for peace of mind, for a period of up to 25 years, and is transferable with a change of ownership of the property.
Sustainable Building Services (UK) Ltd is a member of the Consumer Code of Conduct bodies for energy efficiency and renewable energy products: Home Insulation & Energy Systems Contractors Scheme (HIES) and Consumer Protection Association (CPA).
