How Much Does Your EPC Rating Improve with EWI?

External Wall Insulation (EWI) can significantly improve your Energy Performance Certificate (EPC) rating, but the exact amount will depend on various factors. Such factors include the current condition of the property and the quality of the existing insulation.

What is the EPC rating?

The Energy Performance Certificate (EPC) is a document that provides an energy efficiency rating for buildings in the UK. It is required when a property is built, sold, or rented. EPC ratings range from A (most efficient) to G (least efficient), and they are based on factors such as insulation, heating and cooling systems, and the use of renewable energy. The certificate also provides recommendations for improving the property’s energy efficiency.

In the UK, the average EPC rating for a home is around D. However, this varies depending on the age, construction, and location of the property. Older properties, for example, are more likely to have lower EPC ratings due to less efficient insulation and heating systems. In contrast, newer buildings typically have better insulation, energy-efficient windows, and modern heating systems, leading to higher EPC ratings.

The UK government has set a target for as many homes as possible to achieve an EPC rating of C by 2035 as part of its commitment to reduce greenhouse gas emissions and tackle climate change. This target also aligns with the Minimum Energy Efficiency Standards (MEES) for rented properties. The MEES currently requires a minimum EPC rating of E. The government plans to increase this requirement to a minimum rating of C for new tenancies by 2025 and for all existing residences by 2028.

Homeowners and landlords should aim for at least a C rating to meet future regulations. Moreover, these measures improve the energy efficiency, comfort, and value of their properties. To achieve this, they may need to invest in measures such as upgrading insulation, installing energy-efficient heating and cooling systems, and using renewable energy sources like solar panels.

How much does the EPC rating improve with EWI?

To give a broad estimate, applying EWI to a poorly insulated property could potentially improve the EPC rating by several bands. For instance, a property rated E/F could be brought up to a C or B rating. The rating depends on other factors such as the efficiency of the heating system, windows, and roof insulation.

1. Insulation – This includes insulation in the walls, floors, and roof of the property. The better the insulation, the less heat will be lost, and the more energy-efficient the property will be.
2. Heating and Cooling Systems – The efficiency of the property’s boiler, radiators, air conditioning, and other heating and cooling systems are accounted for. More modern and efficient systems will typically lead to a higher EPC rating.
3. Use of Renewable Energy – The use of renewable energy sources. Solar panels or wind turbines significantly improve a property’s EPC rating. They generate clean energy and reduce reliance on fossil fuels.
4. Windows – Double-glazed windows and other efficient types can prevent heat loss, contributing to a higher EPC rating.

It’s important to note that improving the EPC rating is not just about reducing energy bills and carbon footprint. It can also increase the comfort and value of a property, as well as meet certain regulatory requirements. For example, in the UK, rented properties are required to have an EPC rating of at least E.

However, to get an accurate estimation, you would need to have an EPC assessment. The assessment is performed by a qualified assessor before and after the installation of EWI. This professional will be able to analyse all the factors and give you a precise measurement of how much your EPC rating can improve with EWI.

What about property value?

Improving the EPC rating of a property can add value, but the exact amount can be quite variable. The rationale behind this is quite straightforward. Homes with higher EPC ratings are more energy-efficient, which means lower energy bills for the occupants. These homes are also generally more comfortable to live in, with fewer drafts and better temperature control. Furthermore, as awareness of climate change grows, many buyers and renters are placing increasing importance on the environmental impact of their housing.

However, it’s important to note that while improving the energy efficiency of a property is likely to make it more attractive to buyers and renters, it’s not guaranteed to increase its value by a specific amount. The property market is influenced by a wide range of factors, and energy efficiency is just one of them.

As the graph below shows, there is a significant benefit to improving an EPC rating. A percentage point can increase property value significantly. For example, a 6% increase in property value on a property worth £250,000 results in a property value of £265,000. This is just a simple increase from a band G to F. Whilst the initial outlay for energy efficiency measures can be high, the return is significant. However, the location of the property is still crucial. Areas with higher property value, like London and the South East show limited increase in value.

The improvement from middling to higher bands is more taxing as it requires extreme levels of energy efficiency. The A band of the EPC rating is for properties with an SAP rating of 92-100. Approximately 1% of the UK housing stock can satisfy this level. Therefore, you can envision how difficult this standard is to achieve. However, solutions are present, namely in developing whole communities like Howgate Close.

Source: https://www.moneysupermarket.com/gas-and-electricity/value-of-efficiency/

How much EWI do you need?

The thickness of EWI is dependent on the type of EWI material chosen. The concept of external wall insulation relies on an uninterrupted thermal envelope to minimise cold bridging. Therefore, you will require wall, floor, and roof insulation to effectively improve your EPC rating.

The EWI industry tends to focus on U-values as the barometer for energy efficiency. Current building regulations dictate that new builds and retrofits require a U-value of 0.3W/m²K. At EWI Store, we stock three types of external wall insulation with varying U-values and R-values. Knowing these values allows us to determine what thickness most properties require to lower their U-value; Mineral Wool requires 110mm, EPS 90mm, and Kingspan K5 requires 60m.

If you are considering EWI to improve your EPC rating, let us know in the comments! Alternatively, if you have any questions, drop them below.