Improve the energy efficiency of your home by insulating your internal walls
Internal Wall Insulation

Internal Wall Insulation

Reduce your energy bills dramatically with  internal wall insulation

Internal wall insulation is more commonly known as solid wall insulation and it’s an effective way of keeping heat from escaping through the walls, especially if your home is not suitable for cavity fill.

This type of insulation is usually recommended for homes built before 1920 that do not have a cavity and are solid wall constructed. If your home has a cavity and is suitable for cavity insulation, then this is a better and quicker option.


One-third of heat loss is through the walls of your home

According to the Energy Saving Trust (EST), around one-third of heat loss from most homes is through the walls.  Taking a fabric-first approach to energy efficiency is recommended, and having insulation installed in your home, including internal wall insulation, will dramatically reduce this heat loss.

With National Insurance reported to rise, the energy price cap set to increase and generally the cost of living going up, saving money is at the top of most people’s agenda – making every penny count.

Whether your motivation is improving the energy performance of your home ready to sell it, to keep warm in the colder months, or to save money on those rising energy bills – internal wall insulation is a great solution.


What is Internal Wall Insulation and what are the benefits?

There are an estimated 25 million homes in the UK of which more than 30 percent have been deemed hard to insulate with traditional methods, for example, cavity wall insulation.  The majority of these have a solid wall.

Internal wall insulation is used to insulate solid wall properties by fitting insulation to the inside walls of your home, creating a thermal barrier between the inside of your home and the outdoors, dramatically reducing heat loss.  Additionally, internal wall insulation can improve the acoustic performance of the external walls within your home.

Internal wall insulation is an excellent cost-effective solution to significantly improve the thermal efficiency of your home, reduce energy bills and play a vital role in reducing carbon emissions.

Having internal wall insulation installed can also increase the value of your home by improving the Energy Performance Certificate (EPC) rating.

Benefit from 0% VAT when you install energy efficiency measures

Now is the perfect time to consider upgrading the energy efficiency of your home with internal insulation.  Not only because energy bills are rising at an incredible rate, but you can also benefit from 0% VAT thanks to an announcement made by the government.  This VAT cut will be available from 1 April 2022 until 2027.  As a result, households looking to upgrade the energy efficiency of their homes will benefit from further savings with this recent incentive.  This is applicable when installing insulation and renewable measures.

How is internal wall insulation fitted?

Internal wall insulation can be quick and easy to install, which means that we can minimise the time that your rooms are out of action.

Internal wall insulation is installed by building a stud wall filled in with insulation material such as mineral wool fibre. This is a more cost-effective solution than external wall insulation.


  • Prior to commencing work, an initial survey is carried out by a Retrofit Assessor to check that the internal wall insulation system is suitable for your home.
  • Enabling works are carried out before the internal wall insulation installation.  This includes the extension of electrical sockets and removal of radiators and skirting boards.
  • An insulated stud frame is applied to all exterior facing walls internally, and insulation batts are installed in all areas within the frame.
  • A vapour barrier is applied and fixed to the studs.
  • Plasterboard is fixed on top of the vapour barrier and prepared for the next stage, which is plastering.
  • The walls are then plastered ready for a decorated finish.

What type of insulation do you install?

We use Earthwool glass mineral wool insulation when installing internal wall insulation.  This sustainable product has high performance environmental credentials.

The basic raw materials are silica sand and recycled glass bottles.

Can I get a grant to cover the cost?

Funding may be available from the government’s Energy Company Obligation (ECO4) scheme.  This is an obligation on energy companies to provide funding for energy-saving measures, by the government, to upgrade the energy efficiency of the country’s worst-performing housing and to provide fuel poverty support.  ECO4 funding is available for households with low incomes, in receipt of qualifying benefits, and with a low property EPC rating. This is part of a wider government strategy to reduce carbon emissions, tackle fuel poverty and help householders save money on their energy bills.


How much money will internal wall insulation save me?

The Energy Saving Trust suggests that a household could save up to £660* per year by installing solid wall insulation.

*Source: Energy Saving Trust (EST).  Estimates based on insulating a detached gas-heated home.  Figures are based on fuel prices as of January 2024.

Do you need more information?

Frequently asked questions

Would I have to remove my furniture before installation?

Our surveyor would discuss this with you during your home survey and advise at that time what preparation would need to be done before installation.

How long does it take to install?

A typical property such as a 3-bedroom mid-terrace property would usually take between three and five days to install.

What insulation products do you install?

For the framework – we use a thermally engineered stud, extruded polystyrene bonded to a15mm strip of oriented strandboard.  We use water repellent glass mineral wool slabs.

The insulation that is applied within the frame is an earthwool batt, water repellent glass mineral wool slab.

The overall system is 110mm thick, which includes the plastered finish

Do I get a guarantee with the works?

Yes, you will receive a 25-year industry-backed guarantee.

Get a FREE Survey!

0800 833 018