Insulation FAQ

Any discussion of insulation always seems to bring up a whole range of questions – not least the likes of how much it’s going to cost, how you should go about it, and what real benefits it’s likely to produce. Although a lot depends on the particular home or building to be insulated, at least some of those answers can be found below.

Where and What Should I be Insulating?

The key areas to insulate are the loft, walls and water system. Fitting double glazing and/or draught excluders to windows and doors can also be a big help in cutting down heat loss and so saving energy.

Is Cavity Wall Insulation Effective?

Cavity wall insulation is one of the most effective measures you can take to save energy, slashing around £120 off the average UK home’s annual heating bill. There are also subsidies currently available under the Government’s carbon emissions reduction programme to help meet the cost of installing it, which means that it will effectively pay for itself in a couple of years.

How Thick Should Loft Insulation Be?

The recommended depth is 270mm. If your existing insulation is thinner than this, it is worth bringing it up to the new minimum standard.

How Should I Insulate My Water Pipes and Tanks?

Fit a jacket – at least 75mm thick – to your hot water tank and add suitable insulating material to your hot water pipes; adding this kind of insulation is a very simple job to do and the necessary materials are readily available from DIY stores and hardware shops.

How Much Will it Cost?

With a subsidy under the Carbon Emission Reduction Target (CERT), a typical home can be fitted with cavity wall insulation for around £250 – or £500 if you meet the cost of the whole thing yourself.

Adding a jacket to your water tank will cost around £20 and insulating the pipes in most houses can be done for under £10.

Loft insulation can also be subsidised under CERT, typically costing around £250, or twice that amount if you’re funding it entirely yourself.

Are There Any Eco-Friendly Products I Can Use?

There are a number of eco-friendly insulating materials on the market, though admittedly they aren’t so readily available as their more conventional counterparts. Options include sheep wool – marketed as “Thermafleece” – hemp, flax, straw and cellulose and their main green credentials include low-embedded energy, biodegradability and sustainable production methods. Since they come as “batts” they are particularly suitable for use as loft or wall cavity insulation – particularly when used in new builds or renovation projects to sit between the walls and the dry-lining.

Are There Any Cheap Steps I Can Take Right Away?

Apart from adding insulation to your water tank and pipes if you haven’t already, fitting draught excluders to any doors and windows that need them is probably one of the quickest and cheapest ways to stop wasting heat unnecessarily.

However, perhaps the simplest way of cutting down on heat loss is to shut your curtains as soon as dusk falls; it’s free and surprisingly effective!

How Much Can Insulation Save Me?

Cavity wall insulation should help you save up to 15 per cent of your heating costs – around £120 or more per year for the average home.

Proper loft insulation – up to the recommended 270mm – can save over £150 a year, and cut your carbon footprint by around a tonne of CO2.

The effects of adding insulation to your hot water system are more modest – a jacket saving you £20-£30 a year and pipe insulation a further £10 or so – but they are remarkably cheap to install in the first place and could pay for themselves in under a year!

Is it Really Worth It?

According to the Energy Saving Trust almost half of the heat lost from most homes disappears out via the walls and loft – with the walls alone accounting for nearly a third of the total losses from an un-insulated house. Ventilation and draughts lose a further fifth of the overall total – and poorly insulated window frames and single glazing make up another fifth.

Whether you look at it from an energy saving, cost cutting, or environmental perspective, anything which reduces these sorts of losses has got to be worth it – especially since in many cases help is available to subsidise the cost.