How to improve your EPC rating: common measures explained

You can improve your EPC rating by reducing the heat your home loses and by using more efficient ways to heat it and generate energy.

The best starting point is the list of recommendations on your own certificate, because it is tailored to your property.

In this guide you will learn the common measures, a rough sense of effort and cost, and what to check before you spend money.

This is general information and not advice, so for larger projects it is a good idea to get several quotes and independent advice.

Look up your certificate first if you have not already.

Which measures improve an EPC rating most?

Fabric measures such as insulation and glazing, and heating upgrades such as a new boiler or heat pump, tend to make the biggest differences, but the best option depends on your home.

Measure	What it involves	Cost and disruption	Things to weigh up
LED lighting	Replacing remaining bulbs in fixed light fittings with low-energy ones.	Low cost, no disruption.	A quick win, though the effect on the score is usually small.
Draught-proofing	Sealing gaps around doors, windows and loft hatches.	Low cost, little disruption.	Keep adequate ventilation, especially where there are open fires or gas appliances.
Loft insulation	Laying insulation in the loft to the recommended depth.	Low to moderate cost, little disruption.	Often one of the most cost-effective measures where the loft is accessible.
Cavity wall insulation	Filling the gap between the inner and outer walls with insulating material.	Moderate cost, a day or so of work.	Only suits suitable cavities, and a survey should confirm this first.
Solid wall insulation	Adding insulation to the inside or outside of the walls.	Higher cost, more disruption.	Can make a large difference but needs expert design to avoid damp problems.
Floor insulation	Insulating under suspended timber floors or adding insulation to solid floors.	Moderate to higher cost.	Can be disruptive, and not always practical.
Heating controls	Adding a programmer, room thermostat, thermostatic radiator valves or smart controls.	Low to moderate cost.	Helps you use only the heat you need.
New boiler	Replacing an old boiler with a modern condensing one.	Moderate to higher cost.	Gains depend on how old the existing boiler is.
Windows and doors	Upgrading single glazing or poor double glazing.	Higher cost.	Often slow to pay back, so compare against cheaper measures first.
Solar PV panels	Installing panels to generate electricity.	Higher cost, scaffolding and a day or two of work.	Can raise the score and cut bills, but results depend on roof orientation and shading.
Heat pump	Replacing a fossil fuel heating system with an air or ground source heat pump.	Higher cost, a few days of work.	Works best in well insulated homes, and grant support may be available.

The effort and cost labels above are our general guide, so the indicative costs on your own certificate are a better starting point.

Where should I start?

Start with the cheapest measures that cut heat loss, then move on to larger jobs once you know what they will save.

Read your certificate. The recommendations are listed in a suggested order with indicative costs.
Fix the easy things. Lighting, draughts and loft insulation are cheap and quick.
Treat the fabric before the heating. A well insulated home needs a smaller, cheaper heating system.
Get several quotes. Ask for itemised quotes from installers who are properly accredited.
Check for grants. Some help may be available, as explained in our guide to EPC grants and ECO4.
Get a new EPC. Once the work is done, ask an accredited assessor to lodge an updated certificate.

How do I choose a trustworthy installer?

Choose an installer with the right accreditation for the work, and be wary of anyone who cold-calls or pressures you.

Insulation and fabric work. Look for installers registered with TrustMark, which is the government-endorsed quality scheme.
Heat pumps and solar. Look for Microgeneration Certification Scheme (MCS) certification, which is needed for some grants.
Boilers. Gas boilers must be fitted by a Gas Safe registered engineer.
Guarantees. Ask who provides the guarantee and what happens if the installer stops trading.

It is worth noting that GOV.UK has published warnings about the quality of some solid wall insulation, so check the official guidance if you are considering it.

What are the risks of EPC improvements?

Savings are estimates. Real savings depend on how you use the home and on energy prices.
Poor installation. Badly installed insulation can cause damp, so quality matters as much as price.
Ventilation. Sealing a home up without proper ventilation can cause condensation and mould.
Score is not everything. A measure can cut your bills without moving you up a band.

Common questions

What is the cheapest way to improve an EPC rating?

Swapping remaining bulbs for LEDs, draught-proofing and topping up loft insulation are usually among the cheapest measures, though the effect on the score is often modest.

How much will my EPC score go up?

It depends on the property. The recommendations on your own certificate show the assessor’s estimate of the score after each measure, which is a better guide than any general figure.

Do I need a new EPC after making improvements?

Yes, if you want the register to show the new rating. An accredited domestic energy assessor needs to reassess the property and lodge a new certificate.

Will solar panels improve my EPC rating?

They can, because the calculation credits the electricity a solar PV system generates, but the effect depends on the size of the array and the rest of the home.

Is insulation always worth it?

Not always. It depends on the existing construction, the cost, and whether the work is done well, and poor installations have caused damp and other problems, so it is sensible to use a properly accredited installer.