Energy Saving Plan Builder

When we talk about retrofitting a home we mean improving the energy efficiency of a home through upgrading parts of the home. This could include insulation, double glazed windows, providing renewable energy, heating and hot water or ventilation systems and draught proofing.

Motivations to do this may include making your home more comfortable, less expensive to heat, keeping it warmer, healthier to live in and with reduced carbon emissions, or a combination of these.

Reduce my CO2 emissions provides a combination options for reducing use of fossil fuels and improving energy efficiency of homes to reduce energy bills.

Reduce my fuel bill provides options that prioritise energy efficiency to reduce energy bills, reducing carbon emissions is not prioritised.

Target Zero C02 emissions provides options that prioritise reducing carbon emissions, moving the home away from fossil fuel use.

Retrofit upgrades presented vary depending on what is feasible for your home, based on what the system knows of your home, and the budget you set, across any of the priority options.

In some cases, depending on the homes, the options can be the same or similar.

In other cases, and with a larger budget, bill cost reduction and carbon reduction options may be very different, such as replacing a gas or oil boiler with a heat pump.

Plan Builder uses a range of data sources, including the EPC (Energy Performance Certificate) database. If the EPC was recently produced and is an accurate representation of what your home is, how it’s constructed and what provides heating and hot water etc., it should be highly accurate. If there is no EPC, the system models the home based on nearby homes’ information. If this is not accurate, you can edit the information, if you register your email and login.

Specifying the heating energy source, such as gas or electric, is very important in getting the most useful results, knowing what type of heaters or boiler you have is much less important.

The options Plan Builder provide you are you provide a guide for and between the different upgrades you could make. You can turn options off and on to see the effect they make. Different homes and occupant usage will greatly impact costs and benefits.

We expect them to be most relevant where the system has the most accurate understanding of your home, your motivations (what you want to achieve) and budget available. We recommend professional advice is sought before committing to any works.

1. Plan Builder uses a range of data sources, including the EPC (Energy Performance Certificate) database. If the EPC was recently produced and is an accurate representation of what your home is, how it’s constructed and what provides heating and hot water etc., it should be highly accurate. If there is no EPC, the system models the home based on nearby homes’ information. If this is not accurate, you can edit the information, if you register your email and login.

Specifying the heating energy source, such as gas or electric, is very important in getting the most useful results, knowing what type of heaters or boiler you have is much less important.

The options Plan Builder provide you are you provide a guide for and between the different upgrades you could make. You can turn options off and on to see the effect they make. Different homes and occupant usage will greatly impact costs and benefits.

We expect them to be most relevant where the system has the most accurate understanding of your home, your motivations (what you want to achieve) and budget available. We recommend professional advice is sought before committing to any works.

Professional advice is available from recognised roles such as Retrofit Coordinators, Retrofit Assessors and Retrofit Designers. Further information is available from:

1. Trustmark trustmark.org.uk/find-a-tradesman
2. Elmhurst Energy elmhurstenergy.co.uk/find-an-assessor/
3. ECMK ecmk.co.uk/information/
4. Stroma stroma.com/
5. Quidos quidos.co.uk/

Plan Builder uses a range of data sources, including the EPC (Energy Performance Certificate) database. If there is no EPC, the system models the home based on nearby homes’ information. If this is not accurate, you can edit the information, if you register your email and login.

If you wish to obtain an Energy Performance Certificate, you’ll need to pay for one provided by a Domestic Energy Assessor. A search engine will give you options for local providers. We recommend you shop around, you could expect to pay in the region of £50-100. You only need a valid EPC if you’re renting or selling your home.

An EPC will also give you suggestion on improvements to your home based on reduced the cost of energy, rather than reducing carbon emissions.

The costs Plan Builder provide are offered as a reasonably realistic guide. The cost of building work and allied services and trades has risen over recent years as well as the cost of materials and transporting them. Quotes and estimates for works will vary.

As energy process have risen in recent years, this increases manufacturing and distribution costs, in turn increasing costs of goods and services.

Homeowners and landlords may have equity in their homes and may have the opportunity to access this. Some mortgage lenders have arrangements or products to support retrofit of homes. Some retrofit upgrades may be done at a suitable point in time, such as when the heating and hot water system replacement is due. Independent financial advice should be sought re. any financial arrangements or financial products.

Grants may assist some owners and tenants in certain circumstances. Please refer to HDC’s Home Energy Grants and Funding webpage for more information.

For context, around £15bn is spent every year to install around 1.3m new kitchens across the UK (Retrofitting homes for net zero, HC 453, House of Commons Energy Security and Net Zero Committee, May 2025).