As designers and project managers, when setting the brief for a refurbishment project, ensuring Minimum Energy Efficiency Standard (MEES) and EPC compliance is always on top of the briefing agenda. However, many experts believe that the EPCs of the future will allocate more weight to actual in-use energy performance of a building, and may adopt some of the principles currently deployed in Display Energy Certificates (DECs). We therefore need to be aware of striking a balance between compliance today and futureproofing for tomorrow.

DECs look visually similar to EPCs, however they are used on public buildings over 250 sq m. EPCs are currently valid for 10 years, whereas DECs are shorter term, dependant on the size of the asset, and  – crucially – based on actual energy usage data.

The reduction in validity periods may be something we will see more in the future of EPCs to keep up with changing legislation and the pace of ‘green’ technologies, although this has to be weighed up against the administration necessary to obtain certification.

When it comes to in-use building efficiency ratings, the new kid on the block is NABERS. Introduced to the UK from Australia in November 2020, NABERS measures and verifies actual energy use. Like an efficiency star ratings that you get on your fridge, NABERS provides a rating from one to six stars for building efficiency across energy, water, waste and the indoor environment, and identifies areas for savings and improvements.

We’re seeing NABERS accreditation become increasingly prominent in the market and expect that to continue. We might even see some of the key scoring criteria and ways of measuring them finding their way into the EPCs of the future. NABERS UK has initially been introduced for office buildings, but it’s expected to expand to include other typologies.

It should also be noted that the carbon factors (used to assign carbon dioxide emissions to energy use, based on the source of energy) for EPCs are changing to reflect that the electricity grid has decarbonised significantly since the factors were set in 2011.

The proposed electricity carbon factor of 0.136 kgCO²/kWh is 74 per cent lower than the outgoing figure of 0.519 kgCO²/kWh. This will likely fall further, as the Government is aiming for net zero emissions from electricity from 2035. It is keen to shift away from fossil fuels for heat and hot water and to use electricity instead, supporting the general trend to remove gas from buildings.

However it’s too simplistic to say that if you ditch the gas boiler and get an electric heat pump, you’ll automatically get a better EPC rating. Buildings are inherently complex and have a wide range of uses so it is imperative to consider them on an asset by asset basis.

In summary, the UK Government is aiming to move away from the use of EPCs as we know them today to benchmark energy performance, as their results often do not correlate with actual energy usage in practice. The preferred metric for commercial buildings will make use of metered energy data instead to give us a more accurate picture about how much energy a building is actually consuming, opposed to what it was designed to consume.

Legislation across the energy, EPC and carbon realms will only tighten in the coming years, with landlords and tenants needing to work together collaboratively to improve building stock. Therefore it is vital for owners and occupiers alike to understand the energy and carbon impact of their real estate and make enhancements on their own terms before they are mandated, or assets become obsolete.

Further information

Contact Jack Pugh or Dan Jestico

EPCs vs actual energy use in commercial properties