Advantages and Disadvantages of Internal Wall Insulation

We’re all looking for ways to cut down on our energy bills, whether that’s turning off the heating or switching to energy-saving light bulbs.

However, one methods thousands of UK homes are considering is installing or upgrading their internal wall insulation. After all, insulating your walls is another great way to reduce heat loss, and internal wall insulation is one of the best methods.

While this type of insulation has some advantages, it’s important to consider the potential drawbacks before making a decision. This post will look at the advantages and disadvantages of internal wall insulation, what kind of insulation is best and more.

But first, we must ask:


What is Internal Wall Insulation?

Internal wall insulation is a form of insulation that is applied to the inside wall surfaces of a building.

It can consist of anything from foil, metal or plastic boards and foils to mineral wool slabs and rigid foam panels, all of which are designed to reduce heat loss through interior walls and increase energy efficiency.

Internal wall insulation is typically best suited to solid stone or brick properties built before the 20th century, as it can be difficult to apply to cavity walls.

How Much Does Internal Wall Insulation Cost?

Internal wall insulation is actually up to 50% cheaper than external wall insulation! This makes it an attractive option for people who want to save money and energy.

With internal wall insulation generally costing between £40 and £50/m2 (but sometimes up to £100/m2), the cost of internal wall insulation can vary from £4,000 to £13,000 – but this can depend on the size and type of property.

Can I Get Free Wall Insulation?

£13,000 isn’t exactly pocket change. Luckily, thousands of homes across the UK could be eligible for free internal wall insulation through the Energy Company Obligation (ECO) Scheme.

Whether it’s through the ECO4 or ECO+ Scheme, you could upgrade your home for free and save up to £930 a year on your energy bills. Read our blog posts or contact a member of our team today to learn more.

Benefits of Internal Wall Insulation

There’s a lot to love about internal wall insulation, such as:

  • It’s much cheaper than external wall insulation
  • Lower energy bills through increased thermal performance, as it reduces heat loss through interior walls.
  • Improved air quality due to the internal wall insulation helping to keep the air inside a building free from drafts and dampness.
  • Quieter living due to the insulation helping to reduce noise from outside.
  • Versatile option it can easily be applied to many different wall types, such as timber and stone.

Cons of Internal Wall Insulation

Unfortunately, there are also some drawbacks associated with internal wall insulation. These include:

  • Less effective than external wall insulation.
  • Reduces room size.
  • Installation can be disruptive (but worth doing for the major energy bill savings each year)

What Kind of Insulation Should I Use for Interior Walls?

When it comes to internal wall insulation, there are a range of materials that could be used, each with their own positives and drawbacks.

Some of the most popular options are:

  • Mineral wool: This is made from rock fibres, which can be effective at reducing heat loss. It’s also fire-resistant and acoustically absorbent.
  • Rigid foam board: This is an insulation board made of foam, which can be cut and fitted to walls. It’s a lightweight and easy to install solution, although not always the most cost effective.
  • Plasterboard: If you’re looking for a quick and easy solution, plasterboard may be the best option. It’s affordable and provides good thermal performance but isn’t as effective at reducing noise
  • Thin insulation: This is a type of board insulation that’s applied directly onto the wall. It provides good thermal performance and breathability, but not as much acoustic insulation as some other options.
  • Natural minerals: Natural minerals can be used in wall insulation, such as cellulose or cork. These materials are not only good at reducing heat loss, but also provide acoustical advantages.

No matter what kind of internal wall insulation you choose, make sure you get it installed by a professional who can assess your home and provide an accurate quote for the best results.

Building Regulations for Internal Wall Insulation

Before installing internal wall insulation it’s important to consider building regulations that may prevent you from upgrading the energy efficiency of your home. For example:

  • An uninsulated cavity wall must have a U value of 1.5W/m2 and is prone to cold bridging due to the cavity ties.
  • A solid 225mm brick wall should have a U value of 1.9W/m2, while a solid stone wall can range from 1.7W/m2 -1.4 W/ m² depending on thickness.
  • Building Regulations require maximum U values of 0.3 W / m² or lower, which requires at least 100 mm rigid insulation.
  • Listed buildings will need the permission of local authorities before making any structural changes.

Always make sure that you’re aware of any regulations before starting work on any home improvements.

Is It Worth Insulation Internal Walls?

Internal wall insulation is far cheaper than external wall insulation and offers energy bill savings of nearly £1,000 a year. While it does come with its flaws compared to external wall insulation, it’s a fantastic solution for those looking to improve the energy efficiency of their homes.

With thousands of UK homes being eligible for free insulation through the ECO Scheme, there has never been a better time to upgrade your home and get saving on your energy bills.

So Eco are energy saving experts specialising in home insulation and renewable energy solutions. To discover if you’re eligible for the ECO4 or ECO+ Scheme, complete our free online eligibility checker today.


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