Skip to content
We've helped thousands of households get free energy upgrades in the last 7 years
Warma UK logo
What Is Internal Wall Insulation

What is internal wall insulation?

If you’re living in an older property with solid walls, you might have noticed that keeping your home warm can sometimes feel like a losing battle.  

Internal wall insulation could be the answer you’ve been looking for. This technique involves adding a layer of insulating material to the inside of your externally facing walls, helping to keep the heat in and the cold out. Not only can it make your home more comfortable, but it can also help reduce those ever-increasing energy bills.

Understanding internal wall insulation

What is internal wall insulation?

Internal wall insulation means adding insulating material to the inside of your home’s externally facing walls. This helps keep the heat in during winter and out during summer, making your home’s temperature more stable year-round. 

Types of Internal Wall Insulation 

  • Rigid Foam Insulation: Lightweight panels that are easy to attach to walls. 
  • Fiberglass Insulation: Commonly used and available in batts or rolls. 
  • Mineral Wool Insulation: Great for fire resistance and soundproofing. 
  • Spray Foam Insulation: Provides an airtight seal, ideal for irregular spaces. 

Benefits of insulating internal walls

Energy Efficiency One big benefit is better energy efficiency. Insulation cuts down on the heat that escapes through the walls, so your heating system doesn’t have to work as hard. This means lower energy bills and a smaller carbon footprint. 

Cost Savings Yes, there’s an initial cost, but you save money in the long run on energy bills. Plus, the government offer incentives and rebates for energy-efficient home improvements, which can help with the upfront costs. 

Enhanced Comfort Insulating your walls makes your home more comfortable by keeping the temperature consistent. No more drafts or cold spots!  

Noise Reduction Insulation can act as a sound barrier, reducing noise from outside. 

Moisture Control Proper insulation prevents moisture build-up inside walls, reducing the risk of dampness and mould. This not only protects your home’s structure but also contributes to a healthier living environment. 

How much does internal wall insulation cost?

The cost of insulating internal walls can vary, but on average, it ranges from £60 to £100 per square meter, including both materials and installation. For a more budget-friendly option, using solid insulation boards fixed directly to the walls can cost around £40 to £50 per square meter. If a new stud wall needs to be built for the insulation, the cost can go over £100 per square meter. 

Additional costs like plastering and finishing work can add an extra £20 to £40 per square meter. Necessary repairs or prep work on the existing walls, as well as removing and reinstalling items like radiators, electrical sockets, and kitchen cabinets, will increase labour costs. 

To help offset these costs, government grants such as the ECO scheme are available for qualifying households. These grants can make internal wall insulation more affordable and accessible, allowing more homeowners to benefit from energy savings and improved home comfort. Click here to know more about internal wall insulation grants. 

Warma UK can be your guide to securing these grants and we’ll install the insulation. Click here to see if you’re eligible. 

See if you're eligible for internal wall insulation grants
See if you're eligible for internal wall insulation grants​

Are there government grants available for insulation?

Yes, there are five national grants that provide financial support for people wanting to install insulation at home: the Energy Company Obligation (ECO) scheme, Warm Homes Scotland, Nest (Wales), the Great British Insulation Scheme, and the Home Upgrade Grant (HUG).  

Each of these schemes focus on low-income and vulnerable households, which would typically benefit from this financial support the most. 

Can I get my home insulated for free?

Possibly, it depends on what type of insulation you are looking for and if you meet the criteria. 

The ECO4 scheme can provide 100% funding for certain types of insulation, if the person requesting the grant receives certain benefits. 

Warmer Homes Scotland helps Scottish residents get free insulation for their homes, though the level of insulation covered by the grant will depend on a survey of your home. 

The Welsh government’s NEST scheme will provide free insulation upgrades to eligible homes as well. 

Government grants for loft insulation

Energy company obligation (ECO4)

The most popular grant that helps people lower the cost of roof insulation is the Energy Company Obligation, which offers a grant towards loft insulation for anyone who meets certain requirements. 

Named ECO4 (since it’s currently in its fourth stage), the government scheme works together with energy suppliers to provide financial support for low-income households. 

This includes covering the cost of installing various home improvements, such as internal wall insulation and it also offers free solar panels and heating upgrades to eligible households. 

Potential savings of internal wall insulation 

Internal wall insulation can lead to significant cost savings on energy bills over time. According to the Energy Saving Trust, both external and internal wall insulation can reduce an average detached household’s annual energy expenses by approximately £710, while for a flat, the annual savings would be around £195. 

While the initial investment for internal wall insulation is substantial, typically ranging from £6,000 to £12,000 for a semi-detached home, the long-term savings can be considerable, not to mention the significant increase in your comfort at home. The exact savings depend on factors such as property size, type, current insulation levels, and energy usage patterns. 

Long-term savings and payback period 

Although it may take several years to recoup the initial investment, internal wall insulation results in a warmer, more energy-efficient home that is less expensive to heat. Additionally, it can increase property value. Some sources suggest that the payback period for internal wall insulation can be shorter than that of external wall insulation, making it a potentially more cost-effective option in the long run. 

Homes with internal wall insulation can use up to 32% less energy than those without any form of insulation. This reduction in energy usage can significantly cut costs on monthly utility bills and provide long-term savings, especially given recent rises in energy prices. 

Annual savings estimates 

While the upfront cost can be significant, internal wall insulation can lead to substantial savings on energy bills over time: 

Detached House: Approximately £710 per year 

Semi-Detached House: Around £315 per year 

Mid-Terrace House: About £185 per year 

Flat: Roughly £195 per year 

These figures are approximate, and actual cost and potential savings will depend on the specific circumstances of your property, such as its size, condition, and the insulation materials used. 

Worried about the upfront cost? Warma UK is here for you 

At Warma UK, we’re dedicated to helping you create a warm and energy-efficient home. Internal wall insulation is a fantastic way to reduce heat loss, lower energy bills, and improve overall comfort, especially for older properties with solid walls. With internal wall insulation grants available, upgrading your home’s insulation has never been more accessible or affordable. 

Don’t miss out on the opportunity to enhance your home’s energy efficiency. Contact Warma UK today to learn more about internal wall insulation grants and start your journey towards a warmer, more cost-effective home. We’re here to support you every step of the way.

See if you're eligible for internal wall insulation grants
See if you're eligible for internal wall insulation grants​

Athira Harish