Energy labelling of buildings

Many energy-using domestic appliances are now energy labelled, which gives a clear indication of the energy consumption of that product. This is an effort by the Government to make manufacturers and end-users aware of the need to reduce energy consumption and carbon dioxide emissions. This article will look at the progress towards reducing energy usage in buildings and the move towards displaying an energy label for buildings, together with a certificate that provides information about the energy performance of that building.

Energy labelling

Energy labelling and certification of buildings is part of a wider initiative to reduce energy usage. At present, the 160 million buildings in the EU use more than 40% of Europe’s energy and create more than 40% of its CO2 emissions. Heating fuel accounts for about 55% of the energy consumption; water heating accounts for 25% of domestic and 9% of non-domestic consumption; and lighting for up to 25% of emissions for commercial buildings.

Amendments to the Building Regulations Parts L1 and L2 to improve the standards of energy efficiency in buildings came into effect in 1990, 1995 and 2002. The latest estimated improvements, published by the Regulatory Impact Assessment in 2001, suggest a rise in performance of new dwellings of about 25% and a significant improvement in the performance of non-dwelling buildings. The performance is measured by the reduction of greenhouse gas emissions into the atmosphere. The Government’s Energy White Paper sets out how to achieve the substantial reductions in CO2 emissions required in the coming decades if the level of atmospheric carbon dioxide is to be stabilised. The key elements are:

• encouragement to improve energy efficiency;
• encouragement to select energy sources and generating technologies that produce much less, or no, carbon dioxide.

In addition, EU Directive 2002/91/EC came into force on 4 January 2003.

The Energy Performance of Buildings Directive (EPBD) will greatly affect awareness of energy use in buildings. It is intended to lead to substantial increases in investments in energy efficiency measures within buildings. Legislation must be in place by 4 January 2006 and will affect all buildings, domestic and non-domestic. The major responsibility for practical measures to meet the requirements will fall on building services engineers. The impact of the Directive on the design and operation of building services systems will be discussed below.

In addition, the Office of the Deputy Prime Minister (ODPM) produced a consultation document in July 2004: Proposals for amending Part L of the Building Regulations and implementing the Energy Performance of Buildings Directive. Feedback to this document will end on 22 October 2004. This document contains much detail that will also affect building services design, installation, commissioning and maintenance.

Finally, the Government has also set up the Directive Implementation Advisory Group (DIAG), based at the BRE, to advise it on the energy performance of buildings and the implementation of the EPBD. The Government has established its commitment to addressing climate change through various legal, fiscal and voluntary instruments. These include the Kyoto Protocol, Energy White Paper, Building Regulations and Sustainable Development Strategy. DIAG’s aims are to:

• clarify the requirements of the EPBD;
• provide guidance on possible clarifications and their implications;
• address specific aspects of the implementation of the EPBD;
• highlight the business, as well as the environmental, benefits of a proactive approach to energy performance in buildings.

Implications of the EPBD

The Directive consists of 17 Articles.

Here, we will address those that directly affect building services engineers.

Key provisions in Article 1 are:

• minimum requirements for the energy performance of all new buildings;
• minimum requirements for the energy performance of large existing buildings subject to major renovation;
• energy certification of all buildings;
• regular mandatory inspection of boilers and air-conditioning systems in buildings.

A calculation methodology (Article 3) must be applied at national or regional level to establish the energy performance of buildings.

In addition, the positive influence of the following aspects must be taken into account: active solar systems and other heating and electricity systems based on renewable energy sources; electricity produced by combined heat and power (chp); district or block heating and cooling systems; and natural lighting.

Decisions as to the most appropriate calculation tools are still being made, but it could be a simplified method such as the Dutch standard NEN2916 or a simulated method, such as Energy Plus. The calculation methods must also account for two aspects of building energy performance, defined as the Asset Rating and Operational Rating.

Asset Rating is a measure of the intrinsic performance capability of the building and rates the standard of the fabric, building services equipment and the controls. It would include design aspects that conform to Building Regulations and information generated during testing and commissioning, such as measured airtightness, fan/compressor power, etc.

The Operational Rating is a measure of the in-use performance of the building and is based on actual metered energy consumption.

Figure 1 (from the ODPM Part L consultation) shows how far capital costs for boilers can be increased in percentage terms before becoming non cost-effective.

Article 5 requires that consideration be given to the following alternative systems for heating for new buildings over 1000 m² floor area: chp; district or block heating or cooling; heat pumps; and decentralised energy supply systems based on renewable energy.

This aspect is seen by many to favour the use of VRF/VRV systems that can provide heating and cooling from the same equipment.

Energy performance certificates for buildings (Article 7) must be made available when a building is constructed, sold or rented out and such certificates must not be older than ten years. So that buildings may be compared, the certificate must include reference values such as current legal standards and benchmarks and recommendations for cost-effective investments that can be made in the building to improve its energy performance. Figure 2 indicates how the certification process could work.

Regular inspections

Boilers and air conditioning plant will have to be regularly inspected: Article 8 gives two options for boilers. The first requires a regular inspection of boilers with rated output of 20-100 kW, and for boilers over 100 kW an inspection every two years. For boilers over 20 kW and older than 15 years, there must be a one-off inspection of the entire heating system, including an assessment of boiler efficiency and size compared with the heating requirements. Advice must be given on replacement of boilers, modifications to the system and alternative solutions.

The second option, which the UK is most likely to opt for, requires the Government to ensure there is adequate advice on boiler replacement and needs the building owner to produce a report every two years showing that the boiler achieves all that the first option demands.

Article 9 requires that air conditioning systems over 12 kW output must have regular inspections, including an assessment of efficiency and sizing of plant compared with the cooling requirements of the building.

Finally, Article 10 of the Directive requires that the certification of buildings and inspections are carried out independently by a qualified and/or accredited expert. These can operate as sole traders or be employed by public or private bodies. An advisory group has been formed by the ODPM to review the issues of certificates, training and qualifications for building energy assessors and plant inspectors.

Conclusions

The following questions from the industry will begin to generate some solutions as to the impact on and application to manufacturers, consultants, contractors and servicing companies, although many aspects still need to be resolved.

• Will energy labelling of buildings impact the value and marketability of property portfolios?
• What is the sustainability of first cost approach to construction projects against the true cost eg full life cycle costs?
• Will blue-chip companies’ goals of environmental compliance mean a minimum building energy classification that they are prepared to occupy?