Energy Performance Certificates will be required by all home sellers in England and Wales from June 1st and experts predict that most homes will score poor marks. Whether poor EPC grades will translate into lower sale prices is yet to be seen, but the National Association of Estate Agents has reported a huge increase in properties coming onto the market recently.

Anyone putting their property on the market before June 1st will not have to provide a Home Information Pack of which EPCs are a key requirement. Because EPCs provide detailed information on the efficiency and running costs of a home, it is expected that they will become instrumental in negotiations over price.

The new Energy Performance Certificates will provide ratings similar to those seen on white goods like fridges and washing machines and will grade homes from A to G for energy efficiency and carbon emissions. EPCs will also include estimated annual costs for heating, lighting and hot water and will include recommendations on how to improve a home's efficiency. The reports, prepared by qualified home inspectors, will also advise on which measures ranging from insulation to double glazing will improve a home's energy rating.

Only 6% of the UK housing stock was built after 1995 when tougher building regulations were introduced. This means that most sellers will have to take action to improve the efficiency ratings of their homes. After June 1st, energy aware buyers will have more information available and could easily base a decision between two similar homes on a good energy rating.

Further adding to speculation that EPCs may affect house prices is the strong drive amongst Britons to reduce their carbon emissions. Consumers are choosing energy efficient cars and appliances and there is speculation that many Britons may consider the carbon footprint of a house when making a decision to buy. Add high energy prices to the mix and EPCs alone may put pressure on house prices.

With Home Information Packs expected to cost up to £1,000 per home and a shortage of qualified home inspectors, industry groups are predicting a slowdown in the market if the controversial legislation is not postponed. A House of Lords committee is expected to release a damning report this week and may even block the legislation.

Home Information Packs and EPCs in particular are strongly opposed by estate agents, mortgage lenders, surveyors and even the Law Society. These industry groups believe that HIPs combined with interest rate increases could catapult an already jittery market into freefall.