Energy Performance Certificates: a green bill of health

New certificates will mean buyers can assess a home's energy efficiency and heating costs, says Graham Norwood

The average household in the UK creates about six tonnes of carbon dioxide every year, chiefly from the fuels that we burn - coal, oil and gas - and through routine activities like cooking, washing and keeping our homes warm.

Some emissions may be unavoidable but most property and environmental analysts agree that home owners can reduce the emissions by a series of easy steps.

Most houses built since 1920 have external walls made of two layers with a small air gap or "cavity" between them. Filling that gap with insulating material creates a warmer and more even temperature in your home, and helps prevent condensation on walls and ceilings. The Energy Saving Trust calculates a typical home can save £160 a year this way.

By insulating your loft to the recommended depth of 270mm, you can save wasted energy and another £80 per year, the EST says. Some local authorities even give grants towards the cost of this work.

By trapping air between two panes of glass, double-glazing creates an insulating barrier that reduces heat loss, noise and condensation. If you are on a budget, try secondary glazing - that is, an additional pane of glass screwed to the surrounding frame.

Draught-proofing is the easiest way to make an eco-impact in your home. There are several types of materials available for door and window gaps - brushes, foams and sealants to strips and shaped rubber or plastic - but they should conform to the 'BS 7386', so check with your DIY supplier.

Soon there will be an extra incentive to do this kind of work, especially if you wish to sell your home. From 1 June an Energy Performance Certificate will be issued on every property that goes on the market, allowing buyers to compare the energy efficiency and heating costs of one property with another.

"People should be entitled to this kind of information. You can get this on fridges and washing machines, so why not on a home where the emissions and savings are so much greater?" asks housing minister Yvette Cooper.

The EPC will measure overall energy efficiency based on the Standard Assessment Procedure (or SAP) which takes account of insulation, heating, hot water, lighting, ventilation, the number of windows and the type and quantity of fuel used. Not all of us use our homes in the same way so to allow direct comparisons, energy ratings will be calculated using "standard occupancy" assumptions.

This will assume that during winter the home is heated for nine hours each weekday and 16 hours each weekend day, with the living room at 21C and the rest of the house at 18C.

Most people acknowledge that this information will be good for homeowners - a section will highlight what they can do to improve their home's efficiency and the savings that will generate - but there are mixed views over what the arrivial of EPCs mean for the general property market.

Older homes - including those where listed or conservation area status mean modernisation is difficult or impossible - may become less desireable.

"Period and country houses are defined by their historic windows, doors and construction. Since many are over 500-years-old, we're not expecting an impressive EPC rating," explains Tim Dansie of estate agent Jackson-Stops & Staff.

"EPCs will provide buyers with a better understanding of the running costs of a property and will focus developers into more sustainable building practices. I don't believe it will put buyers off - those who buy a gas guzzler can usually meet the bills that come with it," says Ben Osbourne of London estate agent Friend & Falcke.

Developers are keenest of all on EPCs, because they are confident that new homes will perform best. "We see EPCs as positive. They will help home owners focus on making their homes more eco-friendly," claims Nick Smith, the managing director of Taylor Woodrow Developments.

He may have a point. Homes produce 27 per cent of the UK's total greenhouse gas emissions, over 10 times the amount produced by aircraft, so the drive is on to improve domestic energy efficiency - and save money into the bargain.

The Energy Performance Certificate

The EPC will be issued after an inspection, typically lasting an hour, by a qualified Home Inspector. The certificate will contain the following information:

* Details of your home, its address, date of report and property size in square metres

* A table with headline performance ratings calculated in terms of the average energy use per square metre of floor area, and its "environmental impact" based on carbon dioxide (C02) emissions;

* A table providing indicative costs to light, heat and provide hot water, making standard assumptions about occupancy, heating patterns and the location of the property. This will make any one property easy to compare with another. Energy use will include the energy used in the home and the energy it takes to deliver the fuel to your home. Service or maintenance costs for energy devices are not included.

* A summary of the property's energy performance features, with walls, roofs, floors, windows, heating systems, hot water systems and lighting rated as very poor, poor, average, good or very good.

* Recommended measures to improve the home's performance ratings. These may typically include putting a 150mm jacket on the hot water cylinder, upgrading loft insulation to the recommended 250mm thickness, fully filling wall cavities with fibre, or installing a more energy-efficient boiler. It will not state the cost of these improvements - which will vary according to the cost of local labour and the materials used - but it will contain estimated annual cost savings.

The EPC will be the main component of the Home Information Pack which will be a compulsory element of home sales from June. The seller, usually though the estate agent, will prepare paperwork including deeds, local council searches, planning permissions and building regulations for the property, and the environmental certificate. The government calculates the cost of the HIP at about £500 plus VAT.