How We Raised an EPC Rating from B to A: Case Study in Energy Efficiency

At Mac Surveyors, we’re always looking for ways to help homeowners improve the energy efficiency of their properties. Recently we had the opportunity to work on a project in Great Sankey, Warrington that allowed us to raise the EPC (Energy Performance Certificate) rating of a property from a B to an A. This is a significant achievement as A-rated properties are among the most energy-efficient homes in the UK. As this property was already B-rated all usual measures such as increasing insulation, improving heating systems and low energy lighting have already been done which only left us with a couple of options.

These were the recommendations on the current EPC. We were able to get higher than 95 as we installed a larger solar system than the EPC recommended.

How did we achieve this?

The property in question had higher-than-average energy usage, consuming 6,060 kWh per year, largely due to the charging needs of an EV. Despite this high consumption we were able to improve the home’s energy efficiency with a few different methods.

1. Installing Solar Panels

We installed a Sunsynk 3.6kw Hybrid Inverter designed to capture and utilise the sun’s energy for the home. This move immediately reduced the homeowner’s reliance on traditional energy sources and significantly cut down on electricity bills. The system produces enough energy to cover much of the household’s daytime electricity needs, reducing carbon emissions and lowering the home’s environmental impact.

2. Installing a Solar Battery

To make the most of the solar power generated, we installed a Sunsynk 5.32kw solar battery. This battery stores excess electricity generated during the day for use later, especially during the evening when energy consumption typically increases. By storing more energy instead of sending it back to the grid, the homeowner can rely on solar power even after the sun has set, further reducing reliance on grid electricity and maximising savings.

 3. Installing a Solar iBoost

Rather than install solar thermal we opted to install a Solar iBoost, which uses surplus solar energy to heat the home’s water. By diverting excess energy to the immersion heater, the Solar iBoost ensures that the solar power system is fully utilised, further cutting down on energy costs and reliance on traditional heating methods. This is only possible when a property has a hot water tank with immersion heater.

4. Switching to Smart Tariff

To complement the solar setup, we switched the property to Octopus Go, a smart energy tariff that offers lower rates for electricity used at night. This is particularly useful for charging the electric car overnight, allowing the homeowner to take full advantage of off-peak electricity rates while relying on solar power during the day. With the additional benefit of charging the battery in the winter months for use the following day.

5. Taking Advantage of the Smart Export Guarantee (SEG)

By participating in the Smart Export Guarantee (SEG), the homeowner is able to sell any unused solar energy back to the grid. The SEG provides an additional revenue stream, allowing the homeowner to earn money for exporting surplus electricity generated by the solar panels. This, combined with the savings on energy costs, further enhances the financial benefits of the solar power system.

*It’s important to note that while Smart Tariffs and SEG tariffs don’t directly impact an EPC rating, they are crucial for maximising the benefits of solar energy. Additionally, solar batteries and solar diverters are not currently included in EPC assessments. However, with the release of RdSAP 10 expected in early 2025, these technologies will be considered in future EPC calculations. We will update this post once the new guidelines are implemented to reflect these changes.

The combination of solar panels, the solar battery, the Solar iBoost, the Octopus Go tariff, and SEG payments resulted in impressive savings. Even with higher than average electricity usage, this homeowner saved £1,111 in the last 12 months on energy costs. Over the 25-year lifespan of the solar system, the homeowner stands to save more than £27,000!

The Benefits of an A-Rated Home

Aside from the financial savings, there are numerous other benefits to achieving an A-rated EPC:

• Increased Property Value: Homes with higher EPC ratings are often more desirable, making them easier to sell and typically fetching higher prices.

• Environmental Impact: With the property consuming less energy and generating a portion of its electricity through renewable sources, the homeowner is reducing their carbon footprint.

• Energy Security: The home is now more resilient to rising energy prices and potential supply shortages.

Could Your Home Be More Energy Efficient?

Improving your home’s energy performance doesn’t have to be complicated. With the right you can boost your EPC rating, save on energy costs, and reduce your environmental impact, even if your home has higher than average energy usage. 

If you’re interested in improving the energy efficiency of your home, Mac Surveyors can help if you are based in Warrington, Widnes or St. Helens. We can assess your property and recommend the most effective strategies to improve your EPC rating, reduce your bills, and future-proof your home.