How is an EPC done? exclusive look to the process
Energy Performance Certificates (EPC) were introduced for commercial buildings in April 2008. They are required when a building is built, leased, and sold. EPCs were established by the Energy Performance of Buildings Directive. This was an EU directive. The methodology for complying with this was upto member states.
In England & Wales, the method involves the use of thermal modelling compliance software. The Assessor will visit the building and note the following:
During the site visit, the EPC Assessor will review O&M manuals and rating plates of systems. After the site visit, a model of the building will be constructed using drawings provided. HVAC systems, lighting, building fabric and tenants fit outs are added to the model. The model is simulated using nearest weather files and a Building Emissions Rate established. The building emissions rate is in kgCO2/m2.
As the actual building is simulated, the software also simulates a ‘Reference Building’. This reference building has the same geometry, however, has its own systems and lighting. A Reference Emissions Rate, again in kgCO2/m2 is produced. This Reference Emissions Rate is multiplied by 0.765 to establish the ‘Standard Emissions Rate’.
The Building Emissions Rate is divided by the Standard Emissions Rate and multiplied by 50 to establish the Asset Rating. Therefore, if a Building Emissions Rate and Standard Emissions Rate are the same, an EPC B of 50 Asset Rating points would be achieved.
The EPC scale in England and Wales is dimensionless. It should be noted the current Minimum Energy Efficiency Standard (MEES) is set at a minimum standard of E for lettings. This will be a B level by 2030.
The approach to an EPC in Scotland differs only at the simulation results stage. It is only the Building Emissions Rate that is used for an EPC in Scotland. Therefore, there is no Reference Building to compare against.
The scale for a Scottish EPC is kgCO2/m2. It should be noted that there is no current minimum standard of EPC in Scotland. Scotland has an alternative regime where if the building does not pass the 2002 Building Regulations, it will need a Section 63 Action Plan carried out. The simulation software establishes whether the building passes or fails the 2002 Building Regulations.
Every EPC in England, Scotland and Wales are required to be lodged on a central register. This must be completed by an accredited professional. Each EPC lodged is valid for 10 years from the date of lodgement.
If you have a requirement for an EPC in England, Scotland or Wales, please get in contact at EnergyTeam@kjtait.com