How to insulate your home

In winter, the cost of keeping the home warm can stretch to hundreds and even thousands of pounds. Now, the average annual dual energy bill (gas and electricity) is over £1,300 for homeowners. This is more than double the level of 2006.

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Your central heating is likely to be contributing around 60% to this joint bill, so it’s here you should be prioritising efficiency measures. Fortunately, there are plenty of ways to reduce your heating expenses too and we’ll discuss these below.

Wall insulation

When it comes to home insulation, the walls are likely to be where you start. There’s the opportunity to reduce bills considerably in this department and payback could be in as little as two years – providing you with savings for a number of decades.

Walls can lose up to 45% of the heat your home produces. The colder it is outside, the quicker heat will escape. If your walls are poorly insulated, or worse still, have no insulation at all, you risk losing hundreds of pounds annually on wasted heat.

Not only this, but with insulation fitted you’ll reduce condensation in the home and cut noise pollution too. This shows there are plenty of amazing benefits for making your initial investment.

There are two types of wall your property could be constructed of and as such, two separate insulation methods to consider for how to insulate your home. These are cavity walls and solid walls. Cavity walls have been standard for most properties built after 1920, so you should know which your home would have by looking at the deeds.

How much will I save with cavity wall insulation?

Cavity walls are constructed with two lines of bricks, leaving a gap (cavity) between. This space can be filled with insulation, which is usually pumped through a small, drilled hole in the wall.

The following information shows how much you can expect to save by investing in cavity wall insulation:

Cavity wall insulation

How much will I save with solid wall insulation?

If your walls don’t have a cavity, they’ll be solid. If this is the case, unfortunately it’ll be a little more expensive for insulation but still vitally important to improve efficiency. This is because a solid wall will allow twice as much heat to escape than a cavity wall.

Solid wall insulation is placed over the wall, plugging any gaps and draughts at the same time. Other than reducing energy bills, it’ll also provide extra weatherproofing and reduce condensation. You could also consider insulated plasterboard to help you save on the costs.

Take a look at the table below to find out how much you can save with solid wall insulation.

Solid wall insulation

Loft insulation


After wall insulation, many homeowners start to look upwards, towards the loft in an effort to save money. This is an obvious area to consider as heat naturally rises – so by insulating the loft space you’ll be able to save hundreds of pounds, as warmth is unable to escape through the roof.

When considering how to insulate your home with loft insulation there are two options, based on how accessible your loft space is. If you can get inside, usually through a hatch, you’ll be able to lay insulation boards between the joists and over the beams. This can be pretty hands on, so you may feel safer contacting a professional. You could also be entitled to free loft insulation, so check with your energy company before doing the work yourself.

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If you’re unable to access the loft, you’ll need insulation blown in. In this case, you’ll require the help of a professional and the job should only take a few hours to complete.

Before you undertake the job of fitting loft insulation, ensure to check for signs of damp and have this addressed before continuing. Damp issues will only worsen once insulation is fitted as the loft space will be cooler as a result of the insulation upgrade.

How much will I save with loft insulation?

If you want to find out how much loft insulation will save year-on-year, take a look at the following table:

Loft insulation

Floor insulation

The floor is often disregarded when it comes to insulating the home, but in actual fact there’s the opportunity to save up to £100 a year by improving this area of the property. Not only can you insulate the floor directly, but also fill holes in around the skirting board to reduce draughts.

Floor insulation is reasonably straightforward to fit, so if you feel up to the challenge there’s no reason why you shouldn’t be able to take on the job yourself. The insulation required will depend on the type of floor; mainly stone or wooden.

If wooden floorboards are in place you’ll need to lift these up and fit the insulation in underneath. As with the loft, check for any signs of damp or rot first and have issues cleared up before proceeding. Floor insulation can then be laid in the space below and remember, only insulate the ground floor.

Solid floor insulation comes in the form of rigid boards, which are simply placed on top. You’d then lay tiles, carpet, laminate etc. over this. As the floor level will rise slightly, you may need to shave a little off internal doors and alter electrical fittings.

How much will I save with floor insulation?

For a basic guide on how much floor insulation will help you save, just take a look at the two tables below:

Suspended timber floor insulation

Solid floor insulation

Replacing your windows

Whilst insulation methods are a great way to reduce bills and restrict heat loss, another superb option is replacing the windows. Amazingly, inefficient windows can lose up to 20% of the heat in your home – Wasting hundreds of pounds annually.

For that reason it makes clear financial sense to consider investing in replacement windows, even if there’s a large initial outlay.

By installing double glazed windows you’ll be able to take advantage of the following five benefits:

  • Reduce heating bills
  • Cut carbon dioxide emissions
  • Eliminate draughts and cold spots
  • Keep your home in peace and quiet
  • Limit condensation.

Double glazing begins to lose its efficiency after around 15 years. If your windows are looking a little old and tired or you only have single panes in place, upgrading the units is well worthwhile.

How much will I save with double glazing?

Double glazing is often categorised under a certain energy rating. Take a look at the following table to see how much you’d save with A (the most efficient), B and C-rated glazing.

Window replacement

Replacing your boiler

As we’ve already mentioned above, energy bills have substantially increased over the years and are currently at a record high. With no sign of them coming down in the near future and energy companies seemingly working in unity to increase costs, now’s the right time to consider improvements.

The boiler is a major contributor to your bills too, so when considering how to insulate your home, it’s best to take action and invest in a replacement so you can save over £300 a year.

Today’s modern boilers are much more energy efficient than the ones of 20-30 years ago, primarily because they now work off a condensing operation. This ensures more of the hot gas is converted into heat for the home, rather than being wasted.

Consider this; a boiler of 15-years-old could only be 70% efficient. New boilers are up to 95% efficient.

You’ll have a choice when it comes to installing the new boiler too and preferably you’d opt for an A or B-rated appliance. Combi boilers are also more efficient, providing hot water on demand rather than have it heat up in a water tank. The combi boiler will eradicate the need for a tank in the loft or airing cupboard, so you’ll free up a bit more space too.

How much will I save by replacing my boiler?

We’ve already suggested there’s great potential in replacing the boiler, but the following table indicates your rough annual saving depending on how efficient your current model is:

Boiler replacement

Water tank and pipe insulation

Whilst replacing your boiler would help to reduce energy costs, it’s also worth taking a look at the water tank and pipes. As hot water passes through these, heat can escape the system and lead to inefficiency. Insulating these areas is one of the simplest options available to you, whilst being one of the cheapest too.

If you have a hot water tank in the loft or airing cupboard, you may already find insulation wrapped around it. Check the thickness as ideally it’ll be 75mm to reduce heat loss. In terms of the investment, a new boiler jacket will only cost £15 and you can save £35 annually – A no brainer really.

Then there’s also the pipes, which are just as viable to insulate. You can also do this DIY and insulation bought from any home store can easily fit around the pipe.

How Much Will I Save With Hot Water Tank & Pipe Insulation?

Whilst savings aren’t as large with this type of insulation, the initial cost is seriously reduced too. Therefore it certainly pays to invest. Take a look at the following table to get an idea on how much you’ll save.

Pipe insulation

Smart Meters & Thermostats

Last but not least, we’ll take a quick look at how the heat in your home is controlled, as we try to address the problem of how to insulate your home. Whilst the insulation guidelines above will help to save a small fortune, it’s also financially viable to consider smart meters and upgraded thermostats.

It’s worth pointing out that any type of boiler can be controlled and by doing so you’ll be able to have a better grip on how much heat is being used at any one time. In actual fact, with advanced controls in place, a three bedroomed semi-detached home could save up to £150 a year.

Controls such as a thermostat or smart meter allow you to set individual room temperatures. Staggeringly, reducing the temperature of your home by just one degree can cut bills by an amazing £75.

To add controls to your central heating you won’t necessarily have to upgrade the boiler either. Although as outlined above, if your boiler is over 15-years-old it makes sense to switch to an efficient model.