Residential – Self Assessment Energy Audit

Rural is the most exposed to high wind and colder temperatures, especially in coastal areas. It's even more important to be well insulated and draught sealed in these areas.

Detached houses and Bungalows have heat loss walls to all sides

The older the property the likelihood of less or no insulation, unless it has been upgraded since construction. Some older extensions even with cavity walls were not insulated.

Large areas of glazing should be kept to rooms which can be closed off from the rest of the building in very cold weather. Bigger windows, especially single glazed or old double glazing will have very high heat loss.

Heating a conservatory is very inefficient as large glass areas lose heat very quickly. The heater will have to run almost constantly using lots of boiler gas power or electricity with high heating bills and carbon emissions. Having a conservatory open to the house will act a heat sink to the ground floor in cold weather causing draughts and very high heating bills.

Most heat is lost through your roof, so this is an important area to insulate. If you have no insulation, over £300 a year of heat could be lost through your roof and rooms below the roof will cool very quickly after heating is turned off. You may have good insulation to your main roof, but what about smaller inaccessible roofs or flat roofs. Insulation grants are available for this.

Measure your wall thickness at the window or doors. A 230-250 mm thick wall including internal wall plaster usually means the worst solid brick walls. This is the most expensive to insulate and requires thick external insulation with rendering or both internal and external insulation. Cavity wall bricks are laid so you can only see the long side of the bricks, solid walls show ends of bricks. A 275mm thick wall is usually a cavity wall with a thin 50mm cavity which can easily have injected insulated installed. Any cavity wall constructed before 1996 can be assumed to be uninsulated unless proved otherwise. Don't worry about dampness associated with injected cavity wall insulation as there are now very good bead insulation systems available which don't not encourage damp bridging. Grants are available. Older timber frame and system build walls will have limited insulation, although this is difficult to upgrade and perhaps can only be done with a new outer layer of insulation plus rendering.

15% of heat is lost through the floor. Most solid concrete floors before 1990 are unlikely to be insulated. Solid floors can only be insulated from above with 25mm PIR foam and new boarding below finished flooring but this involve adjusting doors. It is often quite easy to insulate below suspended timber floor if there is sufficient access into the floor void or cellar below.

Single glazed windows have very high heat loss and are very draughty. Perhaps these are unavoidable in a listed building or conservation area but you can still apply glazing film or secondary glazing and heat reflective films.

Timber doors have the highest heat loss. Wooden panelling to doors is often very thin, losing heat quickly. Doors have a fairly large surface area, which is why insulated doors are recommended.

Mechanical ventilation uses electricity and causes heat loss by extracting warmed air if there is no heat recovery.

If your house is draughty, you will notice it is much cooler inside during cold or windy weather. Rubber or foam draught seals should be in place around all window and door openings. Larger gaps to older windows can be filled. You may wish to draught seal some internal doors to keep certain habitable rooms warmer, like the living room. Draught strips are also available for older wooden floor boards and floor perimeters.

Direct electricity heating is the most expensive to run, unless you are super insulated. Oil or LPG heating in rural areas is the worst for the environment with fossil fuel emissions to deliver the fuel, then more fossil fuel emissions to burn it. Instead, investment in a wood chip or wood pellet boiler is cost effective by switching to a renewable fuel source which can be managed and re-grown. Alternatively consider an electric heat pump, see below. Avoid coal burning, unless space restrictions means there is no alternative.

Any pre 1998 boiler is considered to be very inefficient. Don't take advice from heating engineers who tell you 'that's a good quality boiler which is not worth replacing'. An old boiler can use 25% more gas, and with current gas prices, that could mean £250-£300 a year more to run. Some range cookers can use up to 40% more gas then a modern condensing boiler, which could be £400 a year more to run with high carbon emissions.

Don't set your heating temperature too high. It should not be more than 21 deg C or keep just one room warmer. Most families are happy with a setting somewhere between 18˚C and 21˚C for most of the home. Turning you heating down by 1 degree C could save £80 a year. The higher your internal temperature, the more fuel you will use.

Open fires means an open chimney flue. You may even be able to see daylight if you look up the chimney. This is a big hole in your house allowing lots heat to escape. Use a Chimney Sheep or Chimney Balloon to block the flue when not in use. Some older decorative gas fires also have open chimney flue which should be blocked when not in use.

Electric hot water immersion heaters are normally used when there is no gas or heating boiler. An immersion heater needs to have a well insulated storage tank and a timer switch or programmer to control when the electric heating is turned on.

No hot water insulation with electric heating is effectively direct electric heating to your house and cost as much as £56 a week to run! Either dont turn on the hot water or fully insulate as soon as possible.

If you have electric immersion heating, the thermostat is built into the heating element. If hot water is heated from your boiler, a thermostat should be attached mid-height around your hot water cylinder and this turns off the heating water flow to the cylinder once it reaches sufficient temperature, therefore allowing your boiler to use less gas. This thermostat maybe hidden beneath the jacket.

Electric showers are typically 8.5 to 10.5kw. This is as much as 10500 watts of electricity which costs around 3p per minute, or 24p for your average shower, or £88 per person per year for one shower a day. A standard hot/cold mixer shower head may have a flow rate as high a 12 litres per minute or more, especially in areas of high water pressure. This also allows full hot water flow from your boiler giving maximum gas usage for the duration of your shower.

If you still have any old halogen or tungsten lights, throw them away now. LED and CFL lighting can use 10 times less electricity. Also change any old halogen flood lights to LED lighting. LED tube lights can use 35% less electricity than fluorescent tubes.

Solar panels are long considered the be cheapest option to get green electricity into your home. Also consider getting solar panels with a battery storage system so you can also use your solar power overnight. In the summer months, with solar power and battery storage, you will often find you do not use any grid supplied electricity at all, which is a great feeling. You can be 100% carbon neutral or even carbon negative.

Tumble dryers use lots of electricity, they are bad for the environment, and they damage clothing fabric turning it into blue fluff which get caught in the filter.

This wastes electricity, especially if any of your lighting still uses older tungsten or halogen lighting.

How much of the house is heated? Often people may heat the whole house every time the heating comes on, but do you need to heat all of it? Heating only half of the house, or only heating rooms when you are actually occupying them can use half as much energy, saving around £300 a year for the average house.