How to save money on energy with loft insulation

Why do I need loft insulation?

• Keeps the chill out as the heat isn’t escaping, so you get a warmer, cosier home
• It’s effective for at least 40 years, so you will keep getting a good return on your investment
• It reduces your energy bills
• You’ll also be reducing your carbon emissions so you’ll be doing your bit for the planet too (estimates by the Energy Saving Trust show a reduction by approximately 580 KG of CO2 over two years, for a three-bedroomed semi-detached)

There are a few options when it comes to insulating your loft. You could insulate the floor of the loft with mineral fibre roll products and insulating boards, which means that no heat from your home gets into your loft. Instead it stays in your living space. This is the simplest and cheapest process and is easy enough to do yourself if you have some DIY experience.

However, trained installers can fit loft insulation quickly and efficiently, and are particularly useful where access to the loft isn’t easy, or you have damp or condensation problems. If access to your loft is limited, insulating it can consist of blowing or injecting loose, fire-retardant insulation material into the loft. This will need a professional with specialist equipment.

One reason some people are reluctant to insulate their loft is that they want to use it for storage. Unfortunately, if the insulation is to reach the minimum 270mm required thickness of insulation, then this is likely to exceed the height of the joists. This is not recommended as this would mean squashing the mineral wool when you fit the boards on top, making it far less effective at trapping the heat. However, there is a way to get around this.

By Insulating between the joists with mineral wool and then laying rigid insulation boards on top, with wooden boarding on top of that, the loft is then insulated but you are still able to use the loft for storage.

One thing to bear in mind though is that by insulating your loft (as opposed to the roof) the loft space itself will be cold in the winter and hot in summer which means you can’t store any temperature-sensitive items up there. Pipes and water tanks will need to be insulated too to ensure they don’t freeze in the winter. Adding strips of draft-excluding material around the hatch edges means that you don’t get drafts coming through the hatch.

If you wish to use the loft space that keeps at the same temperature as the rest of the house, then you may want to consider installing roof insulation rather than loft insulation. This is a slightly more complex process and would need the help of a professional roof insulation installer, who would fix rigid insulation boards snugly between the roof rafters, which would then be covered by plasterboard.