Energy performance certificates

With the health impacts of climate change well documented, European governments are attempting to limit the threat by reducing emissions of the greenhouse gases that are causing temperatures to rise. One of the major pieces of current European legislation in this area is the Energy Performance of Buildings Directive, which aims to improve the energy efficiency of the EU’s building stock.
    
The main elements of the directive have been implemented in the UK through more stringent requirements in construction (with the up-rating of the relevant Building Regulations) and the introduction of energy certification. Certificates are being introduced to the non-domestic sector over the coming months, and for publicly owned and funded buildings there are additional requirements.

EPCs and DECs
By October this year, an Energy Performance Certificate (EPC) must be made available whenever any building is constructed, sold or let. It contains an assessment of the building’s energy performance as designed - based on the construction materials and the energy systems used - known as the ‘asset rating’. This is expressed on an A-G banding and in addition expected carbon emissions are quoted.
    
Larger public buildings, defined as those “with a total useful floor area over 1,000m2 occupied by public authorities or by institutions providing public services to a large number of people and therefore frequently visited by these people,” will be required to have and display a Display Energy Certificate (DEC) from October. In practice, this will cover buildings funded by public money such as PFI projects, hospitals, and so on.
    
Private hospitals, however, will not be totally exempt. Where private facilities take in NHS patients and are – at least in this sense – publicly funded, they will also be bound by the new regulations.

The operational rating
In addition to the details carried on an EPC, the DEC will have to show an operational rating. While the asset rating is a measure of the design efficiency of a building, the operational rating is dependent on the skill with which energy and the building is managed. It is relatively simple to calculate – much more so than the asset rating, and is less expensive.
    
The operational rating is, essentially, the amount of energy used over a year per unit area of usable floor space. The government defines ‘total useful floor area’ as: “the total area of all enclosed spaces measured to the internal face of the external walls. Included are areas of sloping surfaces such as staircases, galleries, raked auditoria, and tiered terraces where the area taken is from the area on the plan. Excluded are areas that are not enclosed such as open floors, covered ways and balconies.”
    
The total fuel used in the year can be calculated from meter readings (in the case of electricity and gas) or delivery invoices for liquid and solid fuels. Divide fuel consumption by total useful area and you have the basis of the operational rating. This has to be shown on the DEC, which must be on view to the public using the building. As with the EPC, overall performance is displayed in an A-G banding, familiar to most people from the labels on white goods and new cars.
    
The DEC also shows other factual information, such as the carbon emissions, as well as the historical operational rating to demonstrate year-on-year improvements – or otherwise. And a new one has to be produced annually.

Meter readings
The operational rating depends on a full year’s fuel consumption data. For a rating to be provided on 1 October this year, the data has to start from no later than 1 October last year. For those that did not start preparing at this point, there may still be ways to meet the requirement. Organisations with established Monitoring & Targeting (M&T) systems should be able to calculate the required readings from the flow of data. It is expected that there will also be an option to use some form of estimation provided by the energy.
    
As the rating is a summary of a year’s performance, it will be necessary to have the same start and finish dates for all fuels. Meter readings themselves may not represent exactly 365 days consumption so there will need to be some simple rules for adjusting the figures to reach a full year. Most premises will use electricity and gas but again readings may not be taken at the same time, so it will be necessary to have an agreed method of synchronising the data.

Using aM&T
Of course, the whole process becomes much simpler if the meter reading and data collection processes are automated. Over the last five years, automatic Monitoring & Targeting (aM&T) systems have been increasingly common, eliminating many of the repetitive and tedious aspects of meter reading, data collection and reporting. Once aM&T systems are accredited, users will be able to get software upgrades from aM&T suppliers which will allow them to print their own (A3 size) certificates.

Carrying out the assessment
The regulations state that an assessor who carries out the certification process must be ‘independent’ and qualified to national occupational standards (details at www.communities.gov.uk/epbd). Assessors will have to be registered through an approved ‘accredited body’ – there are 12 at present – approved by the Department for Communities and Local Government. These bodies will be able to issue registrations in the coming months in the run-up to the October deadline.
    
The Energy Services and Technology Association (ESTA) represents over 100 major providers of energy management equipment and services across the UK.

For more information
www.esta.org.uk