Facts - Insulation

February 14, 2007 by kotoman

Insulating your home can save you money on your fuel bills, and make your home a warmer and more comfortable place to be. This section describes the different types of insulation available, the savings that can be made, and the grant and discount schemes available to help you insulate your home.

Insulating your home saves on the amount of fuel you use to heat it. Most of the fuel we use comes from burning fossil fuels that emit greenhouse gasses, which causes global warming.

Insulating your house

The different ways of insulating your home are:

cavity wall insulation
solid wall insulation
loft insulation
hot water tank insulation and pipe insulation
draught-proofing
floor insulation

Cavity wall insulation

This involves filling the cavity within the walls of a house (cavity walls are normally found in houses built in the 1930s or later) with insulating material. Cavity wall insulation reduces the heat loss through the walls by up to 40%, thus giving significant savings in heating costs. The reduction in heat loss also leads to an increase in air temperature in the dwelling and, as a result, more comfortable living conditions. Cavity wall insulation is the most cost-effective single insulation measure after loft insulation.

Discounts and grants are available for cavity wall insulation. Full grants may be available if you are over 60 or in receipt of an income related benefit.

Otherwise discounted prices for cavity wall insulation are available through the Big Green Insulation Scheme.

Solid wall insulation

This can be applied to either the internal or external wall of a property. Most houses built before 1930 were built with solid walls. This means there is no cavity within the wall.

External wall insulation is worth considering when repairing the external walls. An insulated cladding is applied to external walls of the house. This form of insulation can be expensive and has a long payback period.

Internal wall insulation can also be installed by placing insulating material behind a layer of plasterboard. This will slightly reduce the floor area of the rooms and should only be considered as part of a major renovation of the property.

Wall Insulation	*Cavity#**	Internal*	External*
Cost of fitting by installer	£280-380	From £900	From £1500 (if walls are being repaired anyway)
Cost recovered	3-5 years	5-6 years	9-11 years

*all information is based on a gas-heated 3-bedroom semi-detached house, with figures from the Energy Saving Trust

Loft insulation

This can save you up to 25% of your heating costs. The recommended thickness of loft insulation is currently 250mm (10″). Loft insulation can be either DIY installed or by a professional installer.

Dont forget that it is important to leave a gap around the eaves, as the loft needs to be ventilated to stop condensation forming, and also to draught-proof the loft hatch to stop draughts entering your home.

Cost	Adding 200mm to existing 50mm of loft insulation	250mm loft insulation where none at present

*all information is based on a gas-heated 3-bedroom semi-detached house

Figures from Energy Saving Trust

Discounts and grants are available for loft insulation. See the Grants and Offers page by selecting the link under ’see also’ on the right-hand menu. Full grants may be available if you are over 60 or in receipt of an income related benefit.

Otherwise discounted prices for loftinsulation are available through the Big Green Insulation Scheme.

Hot water tank and pipe insulation

This can help to keep your hot water hot longer and prevents pipes freezing in cold weather. Hot water cylinder jackets can be fitted to your hot water tank and pipe insulation to your pipes. Both are easy to fit yourself and can be bought from any good DIY store. New hot water tanks will come fitted with foam insulation.

Fitting a thick hot water tank jacket can cut heat loss by up to 75% from your hot water tank. If you already have a jacket which is less than 75mm (3) thick, fit another one around it or replace it completely and you will save even more money.

Cost	Fitting jacket to your hot water tank*	Insulating hot water pipes*
Cost of fitting (DIY)	From £10	From £10
Annual saving on fuel bills	£10-15	Up to £5
Cost recovered	Up to 1 year	2 years

*all information is based on a gas-heated 3-bedroom semi-detached house.

Figures from Energy Saving Trust

Draught-proofing

This is a cheap way of preventing cold draughts entering your home. Draught-proofing materials are available from any good DIY store and can be placed on doors, letterboxes, keyholes and windows.

Draughty doors and windows are a major source of heat loss and fitting draught excluders can greatly increase your comfort and reduce fuel costs.

Cost	Draught proofing*

*all information is based on a gas-heated 3-bedroom semi-detached house.

Figures from Energy Saving Trust

Floor insulation

This can prevent draughts and heat leaks from under your floor. You can apply a regular tube sealant to the gap (like the type you use around your bath), or if you have access under the floor (through the cellar for example), or you need to take the floorboards up, it’s worth insulating underneath on the ground floor. Remember not to block any underfloor airbricks in your outside walls, as the floor space needs adequate ventilation.

Cost	Under floor*	Filling gaps between skirting board and floor*
Cost (DIY)	From £100	Around £25
Annual Saving on fuel bills	£15-£25	£5-£10
Cost recovered	4-7 years	3-5 years

*all information is based on a gas-heated 3-bedroom semi-detached house.

Figures from Energy Saving Trust

No cost/Low-cost options

No cost options:

Close curtains at dusk to reduce heat escaping through windows.

Low-cost options:

Eliminate draughts and wasted heat by fixing draught-proofing to exterior doors. Remember that some ventilation is important.
Cost: around £5
Buy an insulating jacket for the hot water cylinder. This needs to be at least 75mm thick.
Cost: around £10
Saving: £10-£15 per year
Insulate your hot water pipes to stop heat escaping from them.
Cost: around £1 per metre
Saving: around £5 per year
Stop draughts, and heat escaping by filling gaps under skirting boards, with newspaper, beading or sealant.
Cost: around £25
Saving £5-£10 per year
Letterboxes and keyholes can let in draughts. Fit nylon brush seal or spring flap, and put a cover over the keyhole.
Cost: around £5