It is clear how the electric work will improve EPC scores and how an EPC score influences where to focus your money for the greatest impact. This is because the EPC is not a box ticking exercise for compliance because the EPC is a detailed calculation of how energy flows through the building.
What the Assessor Measures
An energy assessor will inspect your commercial building and detail all the electricals and how they are configured. This includes the type of lighting, heating controls, built-in renewables, and the automated cross-building energy management system.
This goes into an estimation of how much energy your building consumes on an annual basis, and the electricals are a considerable percentage of this, especially for buildings where the heater uses gas less frequently.
The assessment looks at installed capacity rather than actual usage. If the building is fitted electrically inefficiently, and regardless of how much the building is used, a lower score will be given. You have to get used to the fact that your energy usage habits matter little to the EPC assessment; they are focused on how much energy your building will consume.
How valuable is lighting? More than you think.
Almost all commercial buildings have lighting loads as the and largest portion of their electrical demand. The Assessor systematically goes through each and every zone and records lighting and how it’s controlled.
Poor scores are given for basic fluorescent tubes with old technology ballasts, and even worse for halogen downlights. LEDs score better, but must be present and operational. Planning to renovate is not enough.
Control of lighting also matters. Improvements are noticed by having automated light sensors, daylight-linked dimming controls, and zone isolation. Buildings score better than the ones with the black box control that allow all lights ON or all lights OFF.
Why heating controls are as important.
Regardless of whether or not your heating runs on gas, the controls are electrical and have a significant impact on your EPC. The difference between a building with basic manual thermostats and one with proper zone control and programming can be several rating bands.
The evaluation will analyze how finely you can manage temperatures in separate spaces. A single thermostat heating and cooling all rooms in a building scores dismally since flexibility is non-existent. If certain spaces require heating while others don’t, you incur energy wastage.
Having thermostatic radiator valves, room sensors, weather compensation, and time controls will all increase your score. For bigger buildings, having a thorough building management system that incorporates all of these makes a positive difference.
Renewable Energy Generation
Installing solar panels or other forms of on-site generation will certainly increase your score, but the extent of the increase depends on how the system is configured. The assessor will consider the capacity of the system, the angle of any panels, and the use of the produced electricity.
It is less beneficial if all your solar generation is exported to the grid compared to systems that use the electricity on-site. Battery storage systems that reduce surplus generation to use on-site later score well because they lower grid electricity consumption.
The electrical infrastructure that supports renewable systems is important too. Proper monitoring and management equipment demonstrates to the assessor that the installation is working efficiently.
Air Conditioning and Mechanical Ventilation
In many commercial buildings, Mechanical Ventilation and Cooling systems consume the highest amount of electricity. As a result, these systems greatly impact your EPC rating.
Legacy air conditioning units with poor energy ratings certainly impact your score negatively. In contrast, modern variable refrigerant flow systems or other high-efficiency cooling systems score significantly better. Basic ventilation also has the same effect. Constantly running basic extract fans score worse than demand-controlled ventilation, which varies based on actual needs.
Systems that recover heat from exhausted air can positively impact your rating. This is because they reduce the heating load, which indirectly increases the efficiency of the entire building.
Power Quality and Electrical Distribution
For industrial or commercial properties with high load requirements, the efficiency with which electricity is distributed throughout the building can positively or negatively impact an assessment. A poor Power Factor indicates that you are drawing more current than necessary to complete the same amount of work, thus, leading to energy waste.
Power factor correction systems reduce this and your surveyor will be able to assess your power factor. Buildings with correction systems installed demonstrate better electrical efficiency.
Optimally supplied Voltage reduction systems that provide voltage which is supplied to electrical equipment also has a positive impact on this assessment. This reduction of supplied voltage also decreases the overall power consumption of electrical equipment, which is reflected in the assessment.
The Timing Question
Any electrical improvements do not count if they are not completed at the time that the assessor reviews your property. Planning permission, quotes, or work being in progress will not help your rating. The assessment only takes into consideration what is installed and operational on the day of the assessment.
This presents a clear problem if performing phased improvements. Either all of the improvements need to be completed prior to the assessment or be fine with having to receive a new EPC in the future to realize the full benefits of your upgrades.
If a property is close to its EPC renewal date, it makes the most sense to time electrical work to be completed just before the new assessment. You would be able to get the improved rating, and in turn, the benefits for the next ten years rather than having to wait.
Understanding the Recommendations
After the assessment is completed, a Recommendations Report and the EPC certificate will be sent to you. This provides a list of suggestions for improvements and their potential impact on the property rating. Electrical upgrades are often listed because they are more easily able to be completed than any structural changes.
Most time, the report will prioritize improvements in terms of cost-effectiveness. Recommended actions such as LED lighting, heating controls, etc. Unfortunately often show up in these reports, as they are low cost and provide significant improvements in terms of rating.
Considering these suggestions is especially important when you are near the bottom of the E ratings for your building. The assessor has tailored recommendations for your building that are likely to result in moving you to the next E rating.