European lead

The government had originally pencilled the next revision to Part L for 2008, but that all changed when the European Union introduced the European Performance of Buildings Directive.

This requires that buildings are rated for energy performance in a much more detailed way than Part L currently provides.

The EPBD is expected to come into force on 1 January 2006 and requires that whenever a building is constructed, sold or rented, a certificate detailing its energy performance is made available to the prospective buyer or tenant. To enable useful comparisons to be made between buildings, the certificate must include reference values such as legal standards and benchmarks.

The EPBD also requires that the prospective purchaser or tenant be provided with a report that summarises the energy efficiency measures that could be adopted within the building. The energy performance certificate and accompanying report represents an important new requirement in the property transaction process. Property lawyers could be accused of negligence if they convey a property (or establish a tenancy agreement) unless valid certification is available.

Display of certificates

the introduction of certification is likely to have a profound effect upon the commercial property sector

Buildings regularly visited by a large number of people, occupied by public authorities or “providing public services” must have the certificate displayed in an area that is clearly visible to the public. In addition, a range of recommended and current indoor temperatures and, where appropriate, other relevant climatic factors should be clearly displayed. This requirement applies to buildings with a total floor area of more than 1000 m2.

It still remains unclear if the definition of “an institution providing a public service” includes large supermarkets, hotels, banks, and other commercial centres. However, the introduction of building energy certification is still likely to have a profound effect upon the commercial property sector and over the next 20 years such labelling is expected to radically improve the energy performance of UK buildings. No organisation that has any concern about either its brand equity or its corporate social responsibility will be happy to occupy a poorly rated building, particularly if it results in company naming and shaming.

Energy rating definitions

A number of important new terms are to be introduced associated with building design and property transactions. The 2004 ODPM Part L/EPBD consultation suggested that the following four energy ratings would be introduced with the 2005

Part L revision:

• New building design rating. A calculation of building energy performance carried out as part of building control submission and used to show compliance with Part L energy performance requirements.
• New building asset rating. A calculation of intrinsic energy performance “as-built”. Asset rating must be better than minimum compliance level. Issued by building control or an approved inspector upon completion.
• Existing building asset rating. Provided to prospective purchaser or tenant and based on the intrinsic energy performance of the building.
• Operation rating. Used for public display and disclosure purposes. Based on actual building performance and energy management, and derived from metered energy data and square meterage.

It is proposed that different types of buildings will be rated using methodologies of varying complexity:

It remains unclear how the odpm intends to undertake the ratings of complex existing buildings

• New dwellings will have a carbon emissions rate calculated using SAP 2005.
• Existing dwellings will be assessed using a reduced version of SAP to enable rating of existing houses to be based upon the minimum requirement for site data collection.
• In 2004 the European Commission issued a mandate to European Committee for Standardisation to develop an EU-wide method for assessing non-domestic buildings. BRE has, on behalf of the ODPM, developed a CEN-compliant methodology called the Simplified Building Evaluation Method.
• Existing non-dwellings will be assessed using a reduced data set version of SBEM together with general assumptions about the type of building to generate a rating.

It remains unclear how the ODPM intends to undertake the rating of complex existing buildings. Unless a standardised method is adopted, there are real risks that potentially absurd (or contradictory) results could be generated by using different tools. This would seriously undermine confidence in building energy labelling.

Operational ratings will be used on the certificates required for public display. The OR will be derived from actual metered energy use and the net treated floor area of the building. The OR is likely to be expressed in kWh/m2 per year and/or kgCO2/m2 per year. The difference between the asset rating and operational rating for a building can provide a useful indication of the energy management practices.

Realising the opportunity

The EPBD provides a significant and realistic opportunity to make substantial reductions in energy use of buildings. Major issues are still to be resolved, including those associated with the delivery of training, qualifications and the quality assurance requirements for independent experts undertaking building certification.

The EPBD will introduce an additional requirement into the process of property transactions. It is also likely to have a major effect upon seller/purchaser and tenant/landlord relationships by introducing, as it does, a new issue for negotiation.

However, these benefits will only be achieved if the certification of buildings is undertaken by trained and qualified assessors operating within a robust competent persons quality assurance framework.