Many thanks for the comments relating to companies offering energy rated windows. It is precisely the fact that some companies offer a sub standard window that the blog post was created, along with the link to the BFRC website.
By viewing this site, our customers can see that what they are getting is the real article. The windows have been tested in accordance with the BFRC regulations and have passed. The other point that these windows are a long term investment is true, and they will over their lifetime save a very noticeable sum of money on the customer's energy bills.