Primary Energy – Not the only consideration whilst designing NZEBs
By the 31st December 2020, the built environment must ensure it is only constructing Nearly Zero Energy Buildings (NZEBs) to comply with the Energy Performance of Buildings Directive (EPBD).
This national requirement for all new buildings to be designed to use very little energy, and to provide for this low energy demand using largely renewable sources, will be the next step for the built environment to take as it aligns with new European and UK energy legislation.
However, the EPBD goes further than just setting this target for new developments – it also sets certain requirements that member states must adhere to, such as measuring the achievement of NZEBs through primary energy.
Moving to a primary energy focused compliance system for new developments would require a shift in mindset for building service engineers, who will need to adjust their specifications and building design to minimise energy use, consider different systems as ‘energy users’, and meet a new primary energy target.
When defining the criteria for measuring NZEBs, the EU were keen to make their definition flexible to allow member states to put into their laws a system that worked for their unique construction industries. Two such factors include the presence of a renewable energy strategy (RES) and whether there will be supporting compliance indicators alongside the primary energy target.
Staying on target: Combining nearly zero energy buildings and low carbon HVAC solutions
Using the primary energy factors listed within the draft SAP 10 methodology and software, we were able to model what a primary energy based compliance system could mean for HVAC specification.
These results were then combined with legally-binding targets and the aims of governmental strategies to provide recommendations on how this could be approached, and the key decisions that Government needs to make in defining nearly zero energy buildings for the UK.