All insulation is designed to keep your home warm and protect your property from cold weather. As such, homeowners tend to consider insulation in the months leading up to winter. There are extra benefits for investing in insulation though, which ensure it’s worthwhile all year round. This includes reducing sound pollution, so your home is quieter.

New homes are typically built with excellent insulation already in place, so realistically it’s older properties that’ll have a problem when it comes to retaining heat. However, it’s easy to address these problems unless your property was built pre-1920 (when solid walls were popular).

Cavity wall insulation

Your property’s walls are one of the biggest culprits when it comes to heat loss. In fact, uninsulated walls will lose a third of the heat produced. What a waste of money! This is natural though, because heat will travel faster between a warm environment to a cool one. So the colder the temperature is outside, the more heat that’ll be lost.

Properties built after 1990 will have some level of wall insulation in place, but those prior to this could be totally exposed. Again, if your home was built after 1920, it’s likely to have cavity walls.

Cavity walls are constructed from two walls with a gap between. This is the cavity and it’s this space that’ll be filled with insulation. Once insulation has been professionally installed, heat won’t be able to pass through your walls and escape the home.

Cavity Wall Insulation Detached Semi detached Mid terrace Bungalow Flat
Annual Saving £240 £145 £95 £100 £75
Installation Cost £720 £475 £370 £430 £330
Payback Time Three Years Four Years Four Years Five Years Four Years
CO2 Saving Each Year 1040kg 600kg 395kg 410kg 325kg

Solid wall insulation

If your home doesn’t have cavity walls, you’ll have solid walls instead. Just as with cavity walls, you’ll be losing plenty of heat if they’re uninsulated. However, for those with solid walls the situation is worse as twice the amount of heat can escape.

Solid walls are likely to impact those with properties built prior to 1920. After this point, cavity walls were favoured. There are a few ways to determine if your walls are solid or cavity.

Measuring them is one possibility and any width less than 260mm is likely to be a solid wall. You can measure the width best by a window or door. Of course, you could also instruct an expert to help determine if your home has solid walls.

Insulation for solid walls can be fitted internally or externally. Both options have their benefits and drawbacks, but as you can see, external wall insulation seems to be a better option all round.

Internal wall insulation:

  • Is a typically cheaper option
  • Will reduce floor space slightly
  • Can be disruptive to home life
  • Requires fittings such as skirting boards to be removed.

External wall insulation:

  • Is more expensive
  • Won’t reduce floor space
  • Fills external cracks and draughts
  • Reduces condensation
  • Improves weather proofing
  • Enhances sound proofing benefits.
Solid Wall Insulation Detached Semi detached Mid terrace Bungalow Flat
Annual Saving £460 £270 £180 £180 £150
Annual CO2 Saving 1,900kg 1,100kg 700kg 800kg 600kg

Loft & roof insulation

Heat naturally rises and as such, it makes sense to insulate your loft and roof to keep warmth inside. No matter the type of roof your property has, insulation will be effective for more than four decades, paying for itself many times over.

Of course, prices will vary dependent on how easy your loft space is to access. If there are no damp problems and access is straightforward, the loft will be easy to insulate and you can even do this yourself.

It’s worth noting that if your loft suffers from any damp problems, it’s important to have these resolved first. Insulation will cause your loft to become a cooler space so damp will only worsen. Professionals will help you tackle damp issues.

For fitting loft insulation, rolls of mineral wool will be used to fill the space between roof joists and another layer to cover these joists. Any competent DIYer will feel comfortable tackling this job without the help of a professional.

Nowadays, lofts are used as excellent extra storage space and if this is your plan, you’ll need to board over the joists after insulation is first laid. Just be sure not to squash the insulation, as this will reduce its quality.

If your loft is inaccessible, this is when matters become a little more complicated and you’ll need to seek the help of an industry expert. Insulation can be blown into the loft space using specialist equipment and this can be completed in just a few hours.

Loft Insulation (0-270mm) Detached house Semi detached house Mid terrace house Detached bungalow
Annual Saving £250 £150 £140 £200
Installation Cost £395 £300 £140 £200
CO2 Saving Annually 1,000kg 620kg 580kg 830kg

Floor Insulation

Heat is lost from your home in a variety of ways and surprisingly for many; the floorboards can be big culprits in this too. Floor insulation can help you save up to £75 each year and there’s the potential to reduce bills even more by plugging the gaps around skirting boards.

The latter is reasonably straightforward for any home DIYer. All you’ll need is a tube of sealant bought from a DIY store. Just be sure not to block under floor airbricks, as floorboards can rot without adequate ventilation.

If you’re considering floor insulation, it’s an easier task for those with older properties. The timber boards can simply be lifted and insulation placed underneath. New homes tend to have solid concrete floors though, in which case rigid insulation will need to be laid on top.

Typically, you’ll only need to insulate downstairs flooring as this has unheated space below. The only time upstairs flooring will need insulating is when the room is above a garage.

Out of the main insulating measures, floor insulation is probably the easiest for those not seeking the help of a professional. For starters, sealing any gaps between skirting boards and floorboards will only cost between £10 and £15. You’ll just need a sealant gun.

When lifting the floorboards to fit insulation underneath, ensure to check for signs of damp or rot. You’ll want the floorboards in as good of a condition as possible before sealing them down.

Solid Floor Insulation Detached Home Semi Detached Home Mid Terrace Home Bungalow
Approximate Annual Saving £75-£95 £45-£60 £35-£45 £70-£80
Approximate Annual CO2 Saving 1050kg 620kg 580kg 830kg
Cost £900+ £900+ £900+ £900+
Suspended Timber Floor Insulation Detached Home Semi Detached Home Mid Terrace Home Bungalow
Approximate Annual Saving £100-£120 £60-£75 £45-£60 £75-£90
Approximate Annual CO2 Saving 110kg 65kg 60kg 95kg
Cost £300+ £300+ £300+ £300+