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Andrew J Ball

On Construction Domestic Energy Assessor (OCDEA) for new-build home energy SAP ratings, providing On Construction Energy Performance Certificates (OCEPCs)

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Quality Assurance


'All in all I am very impressed by the quality of the information provided and of the standard of your work.'

Comment in email from Compliance and Technical Support Executive, National Energy Services, following routine audit of SAP calculation work in July 2010.



Quality of work is assured by


Use of computer software for SAP calculations that has been approved by the Building Research Establishment (BRE) on behalf of the Department for Communities and Local Government.


Membership of the National Home Energy Rating (NHER) quality management system that meets the requirements of BS EN ISO 9001:2000. Members are bound by the rules of the NHER scheme, have to pass a professional examination system, and have their work regularly audited.


Membership of the NHER Accreditation Scheme for On Construction Domestic Energy Assessors.

Members are bound by the rules of the scheme, must meet the required level of National Occupational Standards, have had their work audited for adherence to quality standards, must update their skills and knowledge regularly, and must carry current professional indemnity insurance of at least £1m.


The quality standard for Energy Performance certificates (EPCs), required by Government Legislation, is that 95% of EPCs are within +/- 4% of the true Dwelling Carbon Dioxide Emission Rate (DER) expressed in Kg C02 / m2 dwelling floor area / year. This true value is determined by the Accreditation Scheme's Compliance Team