The Best Insulation for Retrofits

Insulation is now one of the biggest talking points in the world of home improvements. Environmental concerns and rising energy bills have put the poor insulation records of many old houses firmly in the spotlight.

Retrofit insulation – retrospectively fitting insulation onto an existing building – is likely to become increasingly important over the coming years. This guide will provide a basic rundown of the best and most common options available to both homeowners and contractors when it comes to insulation for retrofits.

First of all, though, an important note: the best retrofit insulation depends on a wide range of factors linked to individual properties, including geometry, the current thermal envelope, the property’s age and more.

Expert insight should always be employed on individual builds before insulation is retrofitted; this blog will outline what you can expect ahead of that process.

The Benefits of Retrofit Insulation

Retrofit insulation isn’t the most exciting home improvement in the world – in fact, once it’s done most visitors won’t even notice. However, when it comes to making a house more liveable, there are few better improvements you can make.

Here are some of the key benefits that retrofit insulation can provide for homeowners:

• Energy Savings – Better insulation means less energy required to heat the home, leading to cheaper bills long-term.
• Reduced Carbon Footprint – Homes are a major producer of greenhouse gases. Less energy used means the home’s carbon footprint can also be reduced.
• Increased Longevity – Some insulation retrofits, particularly external insulation, can provide additional protections for the building, further increasing its lifespan.

Things to Consider Before Retrofitting Insulation

While retrofitting insulation comes with a lot of advantages, it’s not for everyone. Various factors could affect the cost-to-savings ratio of a retrofit, or limit the overall amount of insulation that can be fitted.

Here are the three main things to look at before considering whether retrofit insulation is right for a property:

• Planning Permission – Retrofit insulation is usually added to old homes, but some may have restrictions on what changes can be made to the property.
• Structural Concerns – Old homes may not have certain features, like cavity walls, which limits your retrofitting options. Issues like damp also need to be assessed before insulation is fitted.
• Costs – Once everything else has been considered, homeowners will need to weigh up the cost of retrofitting compared to potential long-term savings, while also considering any environmental commitments.

Depending on your goals, retrofit insulation may also need to be paired with other things to be effective. For example, if you want to reduce your costs, you may need to ensure the property’s energy system is up to scratch. You may also need to consider a property’s ventilation, as adding more insulation can reduce the amount of fresh air a house gets.

The Best Locations for Retrofitting Insulation

Various retrofit insulations can be suggested for different homes depending on a whole range of factors, including budget, thermal bridging locations and more.

That being said, the vast majority of retrofit insulation is placed in the three key places where heat is regularly lost.

Roofs

Because hot air rises, a lot of heat tends to be lost through the roof. Roofs are also, usually, one of the easiest places in the home to retrofit insulation.

Unlike with other areas, such as walls, insulation can usually be added to a roof with minimal preparation work. For example, wool fibre can be rolled between floor joists to improve the ceiling’s insulation.

Walls

Walls are the most common consideration when it comes to retrofitting insulation. However, adding insulation to walls can require a lot more work compared to other areas.

Insulation can be blown into cavity walls on relatively new houses (usually those built after the 1920s), but for older homes with solid walls, the options are either internal or external wall insulation.

Internal wall insulation usually involves adding insulating boards to the walls inside the home. This option is usually less expensive than external wall insulation but will also involve removing any existing wall features (such as skirting boards or period features). Internal wall insulation will also reduce the overall size of the rooms.

External wall insulation involves adding an insulating material to the external surface of the building and covering it with a finish. This option avoids having to shrink the inside of the building and can provide additional protection from the elements. However, external wall insulation is commonly more expensive and can also be a problem for period and listed buildings which are expected to keep a certain appearance.

Floors

While floors tend to lose less heat, they can also be a relatively easy place to retrofit insulation.

The options here depend on what kind of floor the property has. Older homes with suspended wooden floors can have insulation fitted in the open spaces with relative ease, while solid floors (often made with cement) will require an additional layer to be added, which can cause issues with fittings like doors.

Best Materials for Retrofit Insulation

As mentioned, the best insulation materials for retrofitting will largely depend on the specific requirements of each job.

There are many different types of insulation available; here are some prominent examples associated with retrofits:

• Mineral Wools – a popular insulation for lofts and floors that can usually be retrofitted with minimal fuss.
• Insulation Boards – these are the go-to option for internal wall insulation; the thickness used can depend on internal factors, such as the depth of window and door frames.
• Blown Fibres – A common choice for retrofitting insulation in cavity walls, allowing the insulation to be blown through holes into the gap.

Of course, there are many other options when it comes to insulation for retrofits, and experts will be able to advise after assessing the property. We hope that this guide provides a useful outline to make discussions around retrofitting easier for both contractors and clients.