Energy house: Just the facts

Updated Tuesday, 29th April 2008
We look at how to improve your house, and be energy saving at the same time

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Take an average three bedroom house somewhere in Britain. Let’s assume that it has a central heating system and appliances that are over 15 years old. Sound familiar? How much energy can you save by upgrading your house? You’d be surprised how worthwhile it is – save energy, save money and save the planet!

We’ve averaged the cost of the products over their expected lifespan – to give you a yearly spend value. Compare that against how much money, energy and greenhouse gases you can save.

Initial values

Electricity

Cost: average spend 6.72p a unit *source npower
Yearly spend: £273
Yearly save: £0
Energy use: 4,000 kWh per year
Carbon dioxide emissions: 1,640 kg

Information: 1 kWh of electricity produces 0.41kg of carbon dioxide. The on peak cost is 6.72p/kWh.
*source Centre for Alternative Technology

Gas

*source npower

Cost: £362
Yearly spend:
Yearly save:
Energy use: 20,000 kWh per year
Carbon dioxide emissions: 3,800 kg

Information: 1 kWh of gas produces 0.19kg of carbon dioxide. The cost is 2.14p/kWh.
*source Centre for Alternative Technology

Items

Green power

Cost: £309
Yearly spend: £36 more
Yearly save: £0
Energy use: no change
Carbon dioxide emissions: reduce by 1,640 kg per year

Information: Green power from some providers costs the same as normal power, but can be up to £3 per month more, depending on supplier.
*sources npower and unit[e]

Did you know that using green power brings your greenhouse gas emissions for electricity down to zero.

Cavity wall insulation

Cost: £460
Yearly spend: £18.4 per year
Yearly save: £55.64
Energy use: reduce by 2,600 kwh per year
Carbon dioxide emissions: reduce by 494 kg per year

Information: cavity wall insulation reduces your gas bill by 13% per annum. It is guaranteed for 25 years, so we’ve averaged the initial cost over this period.
*source Energy Action Grants Agency

Did you know that up to 33% heat loss in your house is through the walls?

Loft insulation

Cost: £430
Yearly spend: £17.2 per year
Yearly save: £55.64
Energy use: reduce by 2,600 kwh per year
Carbon dioxide emissions: reduce by 494 kg per year

Information: loft insulation reduces your gas bill by 13% per annum. It is guaranteed for 25 years, so we’ve averaged the initial cost over this period.
*source Energy Action Grants Agency

Did you know that 25% heat loss in your house is through the roof?

Draught proofing

Cost: £20
Yearly spend: £2
Yearly save: £12.84
Energy use: reduce by 600 kwh per year
Carbon dioxide emissions: reduce by 114 kg per year

Information: draught proofing includes installing foam strips around doors, silicon sealant, brush strips, letterbox and keyhole covers. Expected lifespan about 10 years.
*source Energy Action Grants Agency

Did you know that you can save 3% off your heating bill by fitting draft proofing? *source Energy Action Grants Agency

Hot water cylinder insulation

Cost: £10
Yearly spend: £2
Yearly save: £7.20
Energy use: reduce by 336 kwh per annum.
Carbon dioxide emissions: reduce by 63.84 kg per year

Information: in the year 2,000, hot water costs made up 24% of the average household gas bill.* A hot water insulation jacket has been estimated to last 5 years, and costs have been averaged to this period.
*source Digest of UK Energy Statistics

Did you know that insulating your hot water system can save around 7% of hot water costs?
*source Energy Action Grants Agency

8 compact fluorescent light bulbs

Cost: £24 (£3 each)
Yearly spend: £5.85 (£0.73 each)
Yearly save: £41 per annum
Energy use: reduce by 496.4 kWh per year
Carbon dioxide emissions: reduce by 203.52 kg per year

Information: the lifespan of a compact fluorescent bulb is 10,000 hours. Calculations based on 2 bulbs burning for 5 hours a day, 2 at 3 hours a day and another for 1 hour a day. Old bulbs are assumed to be 100W, replaced by 20W low energy bulbs.

Did you know that energy saving light bulbs last 12 times longer and use a quarter of the electricity of normal light bulbs?

Solar PV system sun station

Cost: £6,700
Yearly spend: £335
Yearly save: £51
Energy use: reduce by750 KW hours per year
Carbon dioxide emissions: reduce by 307.5 kg per year

Information: you can offset the cost of your solar panels by applying for a 50% grant from the government. Solar PV cells are guaranteed over 20 years, so we have averaged the cost over this period.
*source Solar Century based on figures from the Centre for Alternative Technology

Did you know that modern solar cells operate on daylight, not sunlight, so they work even when it’s cloudy?

Central heating and hot water system

Cost: £4,000
Yearly spend: £266.66
Yearly save: £154
Energy use: reduce by 7,206 kwh per year
Carbon dioxide emissions: reduce by 1,369 kg per year

Information: this estimate is based on 5 radiators for a 3 bedroom semi. The average life expectancy of the system would be 15 years, providing the system is installed properly with the appropriate chemical treatment of the water (e.g. inhibitor) and fully maintained. *source central heating information council

Did you know that a new condensing boiler could save you up to 25% off your running costs against an old system?

Fridge

(Hoover HMA28CX 161 litre capacity)

Cost: £330
Yearly spend: £27.5 pounds per year
Yearly save: £22.31
Energy use: reduce by 332 kwh per year
Carbon dioxide emissions: reduce by 136.12 kg per year

Information: refrigerators usually last 12 years, so we’ve averaged the cost over this period. This model uses 308kWh per year.

This example is for illustrative purposes only and does not constitute a product endorsement by the BBC or the Open University.

Did you know new models of refrigerators can be 50% more energy efficient than older ones?

Tumble drier

(White Knight WHK847)

Cost: £200
Yearly spend: £20
Yearly save: £14
Energy use: reduce by 208 kwh per year
Carbon dioxide emissions: reduce by 85.28 kg per year

Information: tumble driers usually last 10 years so we’ve averaged the cost over this period. This model uses 2.5 kWh per load. Older models are assumed to have an energy usage of 3.5kWh per load. Based on 4 washes per week.

This example is for illustrative purposes only and does not constitute a product endorsement by the BBC or the Open University.

Did you know if you put your clothes on the line, you’ll not only have fresher smelling clothes, you’ll also be saving the environment!

Washing machine

(Ariston A1535UK)

Cost: £280
Yearly spend: £23.33
Yearly save: £13.69
Energy use: reduce by 203.84 kwh per year
Carbon dioxide emissions: reduce by 83.57 kg per year

Information: washing machines usually last 12 years, sowe’ve averaged the cost over this period. Estimated on 4 washes per week at 50% energy saving over old models. This model uses 0.95 kWh per wash.

This example is for illustrative purposes only and does not constitute a product endorsement by the BBC or the Open University.

Did you know newer models of clothes washers can save up to 68% of energy over old models?* They also use shorter programs and lower temperatures – saving energy, water and sewage costs!
*source PATH website

Double glazing

Cost: £4000
Yearly spend: £200
Yearly save: £42
Energy use: reduce by 2,000 kwh per year
Carbon dioxide emissions: reduce by 380 kg per year

Information: double glazing usually lasts 20 years, so we’ve averaged the cost over this period. Heat loss through windows by is reduced by 50%. *source Energy Action Grants Agency

Did you know that your home could be losing 20% of its heat through the windows?

 

 

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