If you are looking to replace the glass in your double glazed windows, rather than replacing the whole unit which can be a costly thing to do, then I have just used a great outfit called the Glass Shop.
Initially I was thinking of replacing the whole unit, which was a large double glazed wooden unit over 1.5m x 1.4m. I got a few quotes from standard double glazing companies and these ranged from £900 upwards. I also got a quote from a national glass replacement company which was £500 just to replace the glass. As I was planning to sell the property I decided that spending this much money just on one window would not offer me a good return on my investment! The window was a bit worse for wear outside which is one reason I thought it needed replacing, and also two of the 4 panels of glass were shot, with misty patches on them permanently.
What I didn’t realise was that the outside problems were pretty easy to put right with new beading on the outside of the glass and a coat of exterior woodstain. So really it was the glass that just needed replacing. Two panels of glass and some new beading, including insulation and a coat of woodstain outside, cost me £150. The windows now look great (especially after I sanded and stained the inside too) and really didn’t need replacing at all.
If you want t call the Glass Shop then there number is 01473 805060. I had to chase them a couple of times about the work but they are a couple of good experienced guys who also clean up after themselves.