The energy efficiency of a building has become more in the public eye over recent years with those colourful EPC rating charts….seen with new purchases from washing machines to homes. But what do they really mean and how useful are they? 

The EPC rating gives an energy efficiency grade from A (best-green) to G (worst-red), but it must be understood that it only tells us one half of the story. 

EPC rating tells us about regulated energy loads and this is certainly useful when guiding us to make a purchase decision.

Regulated energy is from controlled sources eg. a light fitting, heater, hot water device, mechanical cooling – these building fittings have a know specification and this information can be incorporated into a design to achieve better energy efficiency.

However there is another less know energy use that we need to think about – unregulated energy.

Unregulated energy results from an uncontrolled source such as the operation of building systems eg. the use of lifts, fridges, printers, cookers, laptops..and so the list goes on. Unregulated energy use varies throughout the day and year, and will also change as users change. The tricky thing here is that user behaviour can only be predicted so it is hard to exactly define operational energy usage when designing for energy efficiency. 

What a lot of words…and why does it matter!? 

Well, in simple terms it does matter if we are serious about meeting the climate crisis goals that are ahead of us. It will also help us reduce the running costs of a building. In some cases, unregulated energy use can account for 50% of total energy use.

Regulated energy use is currently monitored by statutory Building Regulations (Part L), but it is typically up to the building occupants to influence the use of unregulated energy.

Here are some examples of simple and effective steps towards reducing the use of unregulated energy…user behaviour can make a difference:

  • make sure that switches are turned off when not in use
  • have a master shut-off switch
  • turn the lights off when the room is unoccupied
  • limit hot water storage volume and reduce circulation distances
  • have a ‘green’ strategy in the building and work collectively towards conserving energy

…this is just the tip of the iceberg and careful design can also make big steps towards energy efficiency…do get in touch to discuss your project and how we can help.