Had them to put me a bedroom window in and have had to have them back several times because the window wasn't sealed properly it still isn't fixed in my opinion it wasn't put in right in the first place. I wouldn't recommend them to anyone their customer service is non existent !!

Okay, so I've only had my replacement windows for the last 12 days so I would not expect to encounter any major problems with them. I don't count the cracked unit as a problem as accidents can happen and also that was pointed out to me immediately by the fitting crew and was fixed just as they said it would be. The fact that some of the external beading was not properly fitted was of some concern to me but the CEO of the company himself called out the very next day after I had spotted this and put it right. I just wonder how many other double glazing companies would be so quick to rectify such problems? As for the quality of the windows I am, thus far, very pleased. They do exactly what they say on the tin: insulates my flat against both cold and heat, solid build, good security locking and keeps out the noise. In fact after single glazed windows I am amazed at the sound insulation of these windows. The day after they were installed was a very windy day. With my former single glazed and ill fitting windows I would have felt every little draft creeping in through the cracks and heard the wind like it was a hurricane. With my new windows I didn't' even realize how windy it was until I opened one of the windows because I could barely hear a thing!

Bottom line: would I recommend Diamond Windows to others? Definitely!