Create your home energy action plan

The Home Energy Tool estimates the energy efficiency of your home and the cost to heat, provide hot water, and power your lighting and appliances. It also estimates how much carbon emissions are produced as a result.

The Home Energy Tool is made by Energy Saving Trust, an independent organisation working to address the climate emergency.

Find out more on the Energy Saving Trust website.

It calculates the energy demand of your home using information about its size, construction, age, heating type and insulation.

It uses the same calculations as those used to produce an Energy Performance Certificate (EPC). An EPC is produced by an accredited Domestic Energy Assessor (DEA) who surveys your home, taking measurements and recording details about the construction of the building. The Home Energy Tool relies on the information you enter about your home and makes some assumptions based on what you enter.

It makes assumptions about the size of your home, the materials it’s made from, the efficiency of, and other details related to, your heating system, and some other technical information about your property.

The more questions you answer, the less the tool will assume.

The assumptions are based on Energy Saving Trust analysis of housing condition survey data – real-world data representing typical UK homes. The further from typical your home is, the more inaccurate our assumptions may be.

Although the Home Energy Tool gives results very similar to an EPC, it is not an Energy Performance Certificate. The action plan or results from the Home Energy Tool cannot be used in place of an EPC.

The Home Energy Tool uses the answers you give along with Energy Saving Trust’s own assumptions to estimate the energy efficiency of your home. This may lead to different results compared to a full survey of your home by a professional assessor. The EPC may be out of date, especially if you’ve made changes to your home since the EPC was created.

The Home Energy Tool uses measure costs, fuel prices and carbon factors which are reviewed regularly. These will be more up to date than EPCs, especially those created a year or more ago.

Measure costs in the Home Energy Tool are calculated from two parts – a fixed cost and a variable cost. The fixed cost remains a static value regardless of the details of your property, but the variable cost is tied to a specific part of your property. For example, wall insulation costs vary with the area of external wall to be insulated. A house with more external wall to be insulated will have a larger wall insulation cost than a house with less external wall to be insulated. This way, the measure costs we quote you are tailored to your own property.

Each measure cost is based on the most appropriate sources available. Energy Saving Trust analyse data from the Microgeneration Certification Scheme (MCS), Home Energy Scotland Loan and Grant scheme data, installers’ own estimates, and prices collected from online retailers.

The measure costs in the Home Energy Tool are reviewed regularly and are typically updated at least once a year. 

All measure costs are designed to include typical labour and material costs. By typical, Energy Saving Trust mean that their costs will not include the cost of any ancillary or remedial work which may be required for your particular property.

The costs don’t include any additional labour or materials required to fix the state of the property to get it ready for a measure, such as general repairs to the material fabric or to fix damp issues, or any remedial work required after installation should there be any snagging issues. All measure costs include VAT where appropriate. For many energy efficiency measures the current VAT rate is 0%.

The costs presented in the tool are only intended as a guide and are not a definitive quote for the work. Quotes from installers may be higher or lower than the costs provided by the tool. The final cost of work will be influenced by the complexity of the work and the materials required, as well as geography and availability of installers in your area. Energy Saving Trust recommend speaking with three installers or as many as you need to feel confident that the quotes you have been given are competitive before making a decision.

Measure costs on an EPC use a different source to estimate them than this tool does. EPC measure costs may also be based on older cost information, especially if your EPC was created a year or more ago. The costs quoted in the Home Energy Tool are tailored to your property and updated by Energy Saving Trust at least once a year. Both the tool and EPC provide costs only intended as a guide. Energy Saving Trust recommend speaking with at least three installers for the most accurate cost specific to your home.

The Home Energy Tool calculates the energy demand of your home, including the energy needed for heating, lighting and appliances. Each of these energy demands is then multiplied by a fuel price for each of the fuels used.

Energy Saving Trust reviews the domestic energy market and resulting fuel prices typically paid by domestic consumers once a quarter. Their fuel prices are intended to reflect the latest typical prices households are paying. Currently, this means gas and electricity prices set by Ofgem’s Price Cap. Other fuel prices, including oil, LPG and wood fuel, are based on retail analysis or other Government approved sources.

Electricity and gas fuel prices match Ofgem’s Price Cap for a typical household. Their LPG, oil and other fuel prices are derived from Energy Saving Trust research into available fuel prices.

The UK government’s Energy Price Guarantee ended in March 2023. Since then, their electricity and mains gas prices are based on Ofgem’s Price Cap, which is updated by Ofgem quarterly.

Should the energy market return to being a competitive market where electricity and mains gas prices regularly fall below Ofgem’s Price Cap, they will base electricity and mains gas prices off analysis of the available prices using data sourced from Ofgem and the UK Government.

The Price Cap only covers electricity and mains gas. Their other fuel prices, such as for LPG, oil and coal, are sourced from analysis of fuel prices currently available on the market.

The Home Energy Tool calculates the energy demand of your home including the energy needed for heating, lighting and appliances. Each of these energy demands is then multiplied by a carbon factor for each of the fuels used.

Find out more about their carbon factor and energy efficiency and renewable measures on the Energy Saving Trust website.