The Government is committed to introducing Home Information Packs (HIPs), which sellers will have to provide to potential buyers of their house. Originally, it was proposed that the whole scheme should be in place by this June, but the introduction of the main (and most expensive) part of HIPs, Home Condition Reports (HCRs0, has been put back. (Officially, HCRs will still be introduced at a later date. However, many people believe that the Government may decide to shelve these plans indefinitely).
However, HIPs will still be introduced in a more basic form. This means that house sellers will have to provide potential purchasers with the 'search' details on the property, rather than potential vendors having to conduct their own searches or (more usually) paying a solicitor to carry out such searches.
Additionally, vendors will have to supply an Energy Performance Certificate (EPC) for the property. (I think that's probably what you're referring to in your post). This is based on a report provided by a qualified inspector. There is no fixed cost for the survey but it's estimated that a typical fee, for an average-sized house, might be around �400. EPCs are compulsory under EU legislation which was introduced in 2003. The rest of the HIP legislation is specific to the UK (or at least to England and Wales - I'm not sure whether it applies to Scotland & NI).
See here for some information and discussion, on the BBC web site, about HIPs:
http://news.bbc.co.uk/1/hi/programmes/moneybox /5195310.stm
See here for a brief introduction to EPCs:
http://www.carbon-info.org/carbonnews_091.htm
Chris