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How to improve your home’s EPC rating

What is an EPC rating?

If you’re selling, leasing or renting your property, it’s a legal requirement to have an Energy Performance Certificate (EPC). An EPC rates a property's overall energy efficiency. The rating ranges from A (most efficient) to G (least efficient) and is valid for 10 years. It takes into consideration if you have any insulation in your property, the efficiency of your boiler, if you have low energy lighting and more.

Energy standards are becoming more widely known and appreciated. This was seen in April to June 2022 where 86% of new properties were rated A to B. New-built homes are designed to be extremely energy efficient, which can help save homeowners a significant amount of money on their energy bills.

How to improve the EPC rating of your home

If you’re looking to improve your home’s energy performance, there are a number of changes you can make to help increase your overall rating. Some changes are more major than others but all contribute to improving your EPC rating.


Your boiler is a big contributing factor when it comes to your EPC rating as older boilers tend to be less efficient and use more energy to heat your home. To increase the efficiency and to prevent any future problems and costly repairs from arising, it’s important to keep on top of your annual boiler service and any maintenance. You should have your boiler serviced yearly by a qualified heating engineer to ensure that it is operating at its peak efficiency.

Most boilers last between 10-15 years but if your boiler is well maintained it could last even longer. If you are considering replacing your boiler, read our guide here.

If you have an old boiler with a pilot light or you keep having problems with your current heating system, it might be time to upgrade to a more energy efficient model. Doing this will also help improve your EPC rating.

All Glow-worm boilers have an ErP rating of ‘A’ making them highly efficient. View our range of combi, regular and system boilers here.

Heating controls

Heating controls, thermostats and TRV’s help to reduce energy consumption as they allow you to manage your heating more efficiently.

Installing a smart control like Glow-worm’s MiGo can help to ensure that heating is only used when necessary, and that it is set to the most appropriate temperature.

Controlled via an app on your phone, you can programme your heating to only come on in certain rooms and at a time that suits you so you’re not heating your home unnecessarily. Zonal controls are the best option if you're looking to improve your EPC rating further as it provides you with even more control of your heating.

Glow-worm also offer more easy to use thermostats that can still work towards improving your EPC rating. These range from programmable thermostats such as the Climapro2 to analogue timers such as the Climastat select. Using heating controls can assist in enhancing your EPC rating by giving you more control of the heating in your home, also allowing you to be more more conscious of your energy usage.

Home Insulation

Adding insulation around your home is one of the most important factors in improving your EPC rating.

The most important factor in determining how well insulation will work in your home is the R-value. The R-value is a measure of an insulation material's ability to resist heat flow. The higher the R-value, the better the insulation. We recommend installing insulation in the summer as the weather is better for carrying out any building work and you will feel the benefit in the cooler months.

Loft insulation

Loft insulation is easy to install and is a easy way of improving your EPC. It can be made of fibreglass, rock wool, or recycled paper products. In order to achieve maximum thermal performance, it is important to ensure that the insulation is the correct thickness for the depth of the joist space in your loft.

Another option for loft insulation is loose-fill insulation, which is made of fibreglass, cellulose, or mineral wool. This type of insulation is more effective in spaces with irregular shapes or where there are obstacles, such as pipes or ductwork.

Cavity wall insulation

Cavity wall insulation consists of two walls with a gap in between them, with the outer wall made from brick and the inner wall from concrete blocks. A professional installer will fill the space with a material to trap the heat.

By adding this, you’re making your home feel warmer for longer as the insulation traps the heat into your home. This also minimises the length of time you need to have your heating on helping to save you money on your bills.

You can read more about home insulation on our Winter Weather Advice: Keeping Warm In Winter blog.

Internal or external walls

Adding insulation to internal and external walls helps to reduce the amount of heat from escaping through gaps in the wall. Insulation of internal walls can help to reduce the risk of condensation and improve the overall thermal comfort of your home.

Adding solid wall insulation is generally more effective than internal walls, as it reduces heat loss through the entire thickness of the wall. However, internal wall insulation can be more effective in homes with Solid Fuel Heating, because it prevents heat loss through the chimney.

Floor insulation

It is possible to insulate a floor in multiple ways, but the most common and successful way is to install insulation boards. These boards come in different materials, but the most popular is fibreglass.

Another type of insulation that is becoming more popular is foam. This type of insulation is effective at blocking both heat and cold, and it is also very light, making it easy to install.

Upgrade your windows

Double or triple glazed windows

Double glazed windows have two sheets of glass with a gap filled with a gas (usually argon) in the middle. Triple glazed windows work the same but have three panes of glass and two gaps between them.

Upgrading your existing windows to high performance glazing has multiple benefits. As well as improving your EPC rating, it reduces the amount of heat loss through draughts around the windows and will insulate your home from noise outside.

U values

When purchasing energy efficient windows it is important to buy a window with a U-value. The U-value is a measurement of how much heat is lost through a material. The lower the U-value, the better the window is at keeping the heat in.

Energy efficient lighting

Switching to low energy lighting will help you save on energy bills. There are two main types of energy efficient light bulbs available; light-emitting diodes (LEDs) and compact fluorescent lamps (CFLs). Both are better than traditional incandescent blubs but LED’s are longer lasting and a more energy efficient option. This something that you can change gradually, even do one room at a time.

LED lights

LED lights are more energy efficient than traditional incandescent bulbs because they use less electricity and can save you money on your energy bills by emitting less heat. LED lights also last longer than traditional incandescent bulbs, which reduces the overall cost of lighting a home.

CFL lights

Like LED lights, CFLs are more energy efficient than traditional incandescent bulbs and emit less heat than incandescent bulbs. CFLs use about 75% less energy than incandescent bulbs and last up to 10 times longer, so you don't have to replace them as often.

Solar photovoltaic panels

Adding solar panels to your home is a more significant change and there are a few things to take into account before installation, such as available space, cost, and the sort of roof you have.

Solar PV is made from numerous panels on your roof that generates energy from the sunlight. They help to improve your EPC rating as they are an effective renewable method of providing electricity to your home.

Solar thermal systems

Solar thermal power works by collecting sunlight which is then transferred into heat where it is then sorted in a cylinder. This is a more economical and efficient method of providing hot water for everyday living.

Again, panels are installed onto the roof and provide hot water all year round. However, you are more likely to get more hot water in the summer due to having more hours of sunlight throughout the day.

Benefits of improving your home EPC rating

By 2035, the UK government has set out an ambition to have all homes EPC ‘C’ rated in its Net Zero Strategy. With this in mind, people are looking for methods to help improve their home’s EPC rating.

Regardless of what type of property you live in, there are multiple benefits of improving your home's EPC rating to help your home be more efficient.

Lower energy bills

Homes with a good EPC rating are simply more efficient in terms of how they use energy to heat, light and power the residence. This means that they demand less energy for everyday living requirements such as heating and cooling. Less energy use means lower bills, and can result in significant savings over time.

Improved comfort levels for occupants

An improved EPC rating means that a home is more likely to be better insulated, which therefore can retain heat better. This can also result in improved comfort levels for occupants as they are not subject to drafts and cold spots.

Environmental benefits

Reducing the amount of energy that’s wasted by your property can have a positive impact in terms of reducing your personal carbon emissions. That’s because if less energy is being wasted, then you will need to use less overall, particularly when it comes to using gas to heat your home.

Want to find out more?

Whichever options you decide on, make sure to choose the most cost effective and that will provide you a more comfortable home. Read our home energy saving tips for lower bills article for more assistance in saving more money through energy saving measures.