The Technical Bits
THE TECHNICAL BITS
Commercial Energy Assessments at Levels 3, 4 or 5?
There are different levels of commercial energy assessment - levels 3, 4 and 5. Guidance from the Department of Communities and Local Government (CLG) clarifies the Regulations and confirms when the different levels of assessment should apply and hence the qualification level that must be held by the assessor undertaking the energy assessment. In basic terms the differences can be summarised as follows :-
Level 3 Assessments
Existing buildings with frequently occurring characteristics such as simple heating and/or cooling systems, which will often be the same type of systems used in private dwellings. For a building to fall within the remit of a Level 3 assessor, the heating, ventilation and cooling systems will conform to the following limitations :-
- simple heating systems of less than 100kw.
- simple natural ventilation.
- small comfort cooling systems of up to 12kw.
Even these CLG definitions are subject to varied interpretation by different accreditation bodies so it's unlikely that you can make a judgement without talking first with an energy assessor who is required to ensure that he only accepts work that is within his competence. He may need to discuss the details of your property with his accreditation body before he can advise you if the job is within his remit.
This level of assessment uses the SBEM (Simplified Building Energy Model) and the energy assessor undertaking this level of assessment must be qualified and accredited as a Commercial Energy Assessor or CEA (technically referred to as a Non Domestic Energy Assessor or NDEA) at Level 3 or above (Level 4 and 5 qualifications are higher level qualifications and include all of the requirements of a Level 3 qualification).
Level 4 Assessments
Buildings with more complicated heating and cooling systems such as centralised air conditioning systems. Also, all NEW buildings are treated as Level 4 assessments. This level of assessment also uses the SBEM methodology.
The energy assessor undertaking this level of assessment must be qualified and accredited as a Commercial Energy Assessor or CEA (technically referred to as a Non Domestic Energy Assessor or NDEA) at Level 4 or above (the Level 5 qualification is a higher level qualification and includes all of the requirements of the Level 4 qualification).
Level 5 Assessments
New or existing buildings with very complicated heating and/or cooling systems. Large office blocks and other large mixed use buildings would generally fall in to this level of assessment although the decision will be one of interpretation. The complexity of these buildings requires the use of a different calculation methodology called the Dynamic Simulation Model (or DSM) and a key element of the qualification is a thorough understanding of this methodology. Note that DSM can be used to assess all non-domestic buildings but its complexity generally confines its application to only those situations where SBEM cannot be used.
The energy assessor undertaking this level of assessment must be qualified and accredited as a Commercial Energy Assessor or CEA (technically referred to as a Non Domestic Energy Assessor or NDEA) at Level 5. Such a qualification will include a substantial period of practical experience of buildings of this type gained prior to qualification.
Buyer beware.....
The qualification of Domestic Energy Assessor (DEA) which is also a Level 3 qualification does NOT qualify an assessor to complete assessments of commercial property (even if the property was previously used as a domestic dwelling or is built using similar construction methods). This is due to the different calculation methodology that has to be applied to commercial property given the much wider range of uses and many other factors which have to be taken in to account in the preparation of an EPC for a commercial building. The Standard Assessment Procedure (SAP or RDSAP) is used for the assessment of new and existing domestic dwellings.
Another Level 4 qualification which an Energy Assessor may hold is for Display Energy Certificates (or DEC's). Assessments for DEC's are based on a different energy certification methodology of 'operational ratings' (rather than 'asset ratings' which are used in the SAP, SBEM and DSM methodologies). "A DEC and its advisory report are required for buildings with a total useful floor area over 1,000m2 that are occupied in whole or part by public authorities and by institutions providing public services to a large number of persons and therefore frequently visited by those persons". This qualification, though often held by assessors who also are qualified as Commercial Energy Assessors, does not in itself qualify an assessor to prepare EPC's for commercial property.