How to insulate your home (and why you should)

Insulation is arguably the most practical and cost effective way of making your home more energy efficient . If you’re worried that insulation is expensive, and complicated, we’re here to help! With rising energy prices and chilly winters, there’s never been a better time to invest in insulating your home and insulation is a great way to keep your house toasty warm. 

Cold Weather

Insulation works because it stops heat from escaping and there are a number of benefits to insulating your home: 

  • It keeps your home warmer without heating
  • It can save up to 50% of your heat escaping
  • It reduces your carbon emissions 
  • It saves you money on your utilities bills 
How much does insulation cost?

Why should you bother adding more insulation? Well, the Energy Saving Trust says in-wall (or cavity) insulation costs £400 to £500 to install, and can save an average three-bedroom home up to £160/year on its bills. Loft insulation costs about £300 and can save £150/year. Depending on your home, the savings you can make are significant. Just imagine what you could spend your savings on!

Loft Insulation Detached House Semi Detached House Mid Terrace House Detached Bungalow
Fuel Saving (£/year) £240 £140 £135 £200
Fuel Savings (5 years) £1200 £700 £675 £1000
Cost to install £395 £300 £285 £375
What you could buy... New living room furniture Week long holiday for two HDTV and home cinema system Designer handbag

The great news is that there are even free ways to insulate your home. 90% of homes that need insulating can get it for free. To find out if you’re eligible, visit British Gas.

Where should I insulate? 

Insulation can happen in a variety of places around the home, and cavity insulation is a guaranteed way to keep your house warm. If your house was built between 1920 and 2000, it’s likely to have cavity walls. This means that in between two brick walls, there will be a gap of up to 50mm. Many people choose to insulate their wall cavities, but this requires a specialist and can be expensive. Find out more or call the Energy Advice Line on 0300 123 1234 to see if you are eligible for funding. 

 If your home was built before 1919, the walls are likely to be solid brick without any cavity insulation. You can still insulate solid walls, both on the interior and the exterior. Most people choose exterior insulation of walls, but check that you don’t need planning permission before you hire a builder.

1. Loft insulation 

Insulating your loft is easy and will save you money on your energy bills. Even if your loft is already insulated, ‘topping up’ will still improve the efficiency of your home.
Loft Insulation

Loft insulation is most commonly found in the top of a house, as it is the most effective and economical way to keep a home warm. There are different sorts of loft insulation, but even if you already have some insulation you can still ‘top-up’ and improve the efficiency of your home. 

You can also insulate your floor, this can be done by lining between the floor boards and your carpet, or by hiring a professional to put foam insulation under the floor boards. 

Loft insulation comes in two forms. Let’s look at the features of both, so you can see which type bests suits your needs. The more you know about insulation, the more money you can save!

Superglass   Rockwool
 • Soft texture  • Solid texture
 • Flexible  • Very strong
 • Made from recycled glass  • Made from volcanic rock
 • Lightweight  • Heavier / denser
 • Cheap   • Reduces sound

If you have a small loft space, then Superglass might work best for you. If in the future you intend to use your loft space as a room, you may want to use Rockwool as it is denser than Superglass and can minimise noise. If you’re not sure, speak to one of our team instore, we’re always happy to help.

Measuring for loft insulation

2. Pipe lagging

Insulating, or ‘lagging’ your water tanks, pipes and insulation behind radiators can reduce the amount of heat loss. This way you spend less money heating water up, and your water stays hot for much longer. 

Exposed pipes can lose huge amounts of heat, particularly when they are in a loft or garage that is unheated.  Richard Bazley from Bradfords Ilminster says, “You should always insulate your pipework. No insulation means you’re heating your loft for no reason. Your house will get colder and you can cause problems with pipes. By insulating your pipework you stop heat loss to the roof.”
Pipe Lagging

Pipe insulation is really simple and you can insulate exposed copper pipes yourself, for example near to the boiler. But for underfloor pipe insulation it’s always best to hire a professional. 

This type of insulation prevents condensation forming on the outside of the pipe, and protects the pipes from bursting in very cold weather. Insulation thicknesses vary so the thicker the insulation width the more heat you save. A final benefit of this type of insulation is that it reduces noise from your hot water system, so also gives you a quieter home.

The other main places worth insulating around the home are the edges of windows and doors

3. Roof and floor

Roof insulation or floor insulation is a great way to keep your house warm in winter. We advise that you use it wherever possible. Floor insulation is specifically covered in the Part L regulations which can be found here


There is a range of roof and floor insulation available to you. Superglass, or Mineral Glass insulation similar to the lightweight loft insulation mentioned above, can be used under flooring or as part of roof insulation. But in these areas, there are also special types of insulation that can be used. The first is a thin foil insulation often used under your roofing felt. This is called Multifoil, and is very thin, but very effective at retaining heat. 

Roofing boards are also used to insulate when houses are being built. If you have a loft conversion it would be worth asking for extra insulation, and roofing boards are perfect for this. Thin, durable and very effective, these rigid boards keep heat where it’s needed most. 

Under floor and roof insulation can also be made from Polystyrene, which is a cheaper alternative to Superglass. Polystyrene is a synthetic and lightweight material that stops heat escaping. 

When you are considering roof or underfloor insulation be sure to consult a professional who can guide you in whichever type of insulation best fits the job.

4. Wall

Wall insulation is often already included in your house. If your home was built after 1920 it will already have cavity insulation. The cavity refers to the gap between two layers of bricks. Cavities can be filled with a variety of different types of insulation. The most common would be Rockwool or Mineral Glass, but other more environmentally friendly varieties are now available too. 
Wall insulation

If your home has solid walls, it is still possible to insulate them. You can either have exterior insulation coatings added to the brickwork, or interior boarding added. The advantage of exterior insulation is that it doesn’t detract from the size of your property inside, but the interior coating is often more affordable. 

If you have more questions on what types of insulation are available, then see our next blog post. Keep checking back for more tips and tricks on home maintenance. Alternatively, our DIY specialists are ready in store for your questions or simply call us on 0344 846 1133.