The site assessed was the Crew Building located at the King’s Buildings Campus of the University of Edinburgh. Originally built in the 1930s, the building spans over 1,900 m2 and comprises lecture theatres, tutorial rooms, offices, a canteen and computer rooms. The University recently invested in a CHP plant and was keen to look what the asset rating of Crew Building would be.

What did Carbon Masters do?

Carbon Masters carried out the energy assessment leveraging Carbon Guru for Low Carbon Buildings, an innovative cloud based tool used for Building Information Modelling (BIM). The process included:

–       Creating a 3D model of the building using our Carbon Guru BIM tool set

–       Carrying out a physical site survey;

–       Feeding the survey data into our Carbon Guru energy analysis tool;

–       Generating an Energy Performance Certificate (EPC);

–       Calculating the operational rating of the building based on energy consumption data from energy bills and meter readings and;

–       Comparing the Operational Rating v/s the asset rating and identifying areas of improvements to bridge the difference.

Observations

Two key observations were made as a consequence of the assessment:

1. The asset (EPC) rating of the Crew Building was a ‘D’ rating at 59 kgCO₂/m²’. This rating is, in our view, a consequence of the building being supplied by the CHP plant which otherwise would have been a lot higher considering the stone wall construction and single glazed windows which have poor thermal performance.

2. The assessment also indicated that the Operational Rating for the site is at 88 kgCO₂/m², a difference of 29 kgCO₂/m², which implies that the building is theoretically capable of a 33% reduction in CO₂ emissions if the operational rating could be brought into line with its asset rating. Carbon Masters carried out a detailed analysis of the building fabric performance by running various scenarios to identify potential areas for improvement and associated cost savings.

Key areas of improvement identified

Three potential areas of improvement to the fabric of the building were identified that, if implemented, would bring about a 24% reduction in CO₂ emissions i.e. 41.49 tonnes per year. A further 9% reduction could be achieved by improving operational efficiency of the building. The areas of improvement identified were:

• Install Double Glazing (low emissivity, air filled 4-16-4mm) – Installing double glazing could potentially save 9.88 tonnes of CO₂ per year.
• Lighting Improvements – It was estimated that switching to T5 lights could save around 3.95 tonnes of CO₂ per year.
• External Wall Insulation – External Wall Insulation has the largest savings potential of up to 27.66 tonnes of CO₂ per year

The new EPC confirmed that the building is therefore regulatory compliant under regulations contained in the Energy Act 2011, which will make it illegal to sell, rent or let any property with an EPC rating worse than E after 2018.

Benefits

Achieving this 33% reduction would represent significant cost savings, as well as reducing over 200 tonnes CO2 over the next 5 years.