Energy bills in the UK continue to rise, and for many households in Pembrokeshire, keeping warm during the colder months has become increasingly expensive. One of the simplest and most effective ways to tackle this problem is by improving insulation. In particular, cavity wall insulation has become a highly recommended upgrade that can make a noticeable difference to both comfort and energy costs.
This step-by-step guide explains exactly what cavity wall insulation is, why it matters so much for homes in Pembrokeshire, how the process works, and what kind of financial support is available through Government schemes such as ECO4 and the Great British Insulation Scheme (GBIS). We’ll also show how Green Homes Group can help you arrange a free home survey, check your eligibility for funding, and connect you with reliable local installers.
Many houses built from the 1920s onwards were designed with cavity walls — two layers of brick with a gap between them. The purpose of this gap was originally to help prevent damp. However, it also provides a route for heat to escape, meaning homeowners spend more on heating while still struggling to keep their homes warm.
Cavity wall insulation fills this gap with a material that traps heat inside. It can be made from mineral wool, polystyrene beads or foam, each designed to reduce heat loss and improve efficiency. When installed correctly, the insulation creates a thermal barrier that can cut energy wastage by more than a third.
Pembrokeshire’s location on the Welsh coast makes it more exposed to wind, rain and damp conditions than many inland areas. These weather patterns increase the rate of heat loss in uninsulated properties. At the same time, many houses in the county were built before energy efficiency became a priority, meaning they are often poorly insulated.
Adding cavity wall insulation offers a straightforward way to address these challenges. Not only does it help homes stay warmer in winter and cooler in summer, but it also brings down heating costs significantly. For families facing rising bills, this can provide much-needed relief. Beyond the financial savings, insulation improves living comfort and contributes to lower carbon emissions — an important factor as Wales continues to work towards its climate targets.
Not every property in Pembrokeshire can benefit from cavity wall insulation, so the first step is assessing suitability.
Indicators your home might be suitable:
However, only a professional survey can confirm whether your property is truly suitable, as damp issues or structural defects may need addressing first.
Once you suspect your home may be suitable, the next step is arranging a professional survey. This is where Green Homes Group can help. We’ll organise a free home survey to:
This step is crucial to ensure the installation is safe, effective, and long-lasting.
Cavity wall insulation is installed using specialist equipment but causes very little disruption. A typical installation involves:
The process usually takes less than a day for most houses, and you can continue to live in your home during installation.
Once installed, cavity wall insulation requires no maintenance. It’s designed to last the lifetime of the property. However, good aftercare includes:
Cavity wall insulation provides both immediate and long-term benefits:
The ECO4 scheme provides funding to improve the energy efficiency of homes, with a strong focus on helping low-income and vulnerable households. If you receive benefits such as Universal Credit, Income Support or Pension Credit, or if your home has a poor EPC rating, you may be eligible for full funding to cover cavity wall insulation.
The GBIS is designed to reach households that may not qualify for ECO4 but still need help improving efficiency. In Wales, homes in Council Tax bands A to D with an EPC rating of D or below may be eligible for partial funding. This makes insulation more affordable for families who don’t qualify for full grants but still want to cut their bills.
Both schemes come with rules and paperwork that can feel confusing. Green Homes Group can simplify this process by checking your eligibility, explaining the options clearly, and guiding you through applications. Because we are not installers ourselves, we offer impartial advice and then recommend trusted local professionals from our network to carry out the work.
The cost of cavity wall insulation depends on the size and type of property. A small flat or bungalow might cost around £700, while a larger detached property could reach £1,500 or more. These figures are typical without financial support. With ECO4 or GBIS, the price can be cut dramatically — in some cases reduced to zero.
When you consider that many households save around £250 annually on bills, the investment pays for itself quickly. Even without grants, most homeowners recover the cost within four to six years, and after that the savings continue year after year.
Some homeowners are hesitant because of persistent myths. One common concern is that cavity wall insulation causes damp. In reality, damp problems only arise when surveys are skipped or the work is done poorly. With a proper assessment and a skilled installer, insulation should not cause issues.
Another misconception is that it is too expensive. With Government support, many Pembrokeshire households find the cost affordable, and in some cases completely free. Others worry that older homes cannot be insulated. While very old stone cottages may require different approaches, many pre-1990 properties in the county are perfectly suited to cavity wall insulation.
For anyone in Pembrokeshire considering cavity wall insulation, the most sensible starting point is a professional survey. At Green Homes Group, we arrange this completely free of charge and without obligation. The survey will confirm whether your property is suitable, highlight the potential energy savings, and outline which funding options may apply.
Beyond the survey, we help with the often-complicated process of applying for ECO4 or GBIS support. Our team ensures you understand your eligibility, assists with the paperwork, and connects you with experienced, trusted installers from our network. Since we are not installers ourselves, our advice is impartial and focused entirely on finding the right solution for your home.
Cavity wall insulation is one of the most effective home improvements available to Pembrokeshire residents. It reduces heat loss, saves hundreds of pounds a year on bills, improves comfort and helps lower carbon emissions. With Government schemes offering generous support, there has never been a better time to take action.
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