We wish we had never entertained using Everest, its been a blight on our lives for the last 2 years. After the install, which was months late, we reported issues, and when fixing one issue they created others. The end result is that 2 windows where completely replaced, only to be even worse than the first attempt. When you pay for triple glazing, you don't expect to tape up the windows to stop the wind blowing though them, where they have been pulled out of shape, by installers who are on a bonus the more windows they fit in a day, no care is taken at all. One time after an adjustment we needed to call them out again as the window could be popped open when locked with a push. This was found while cleaning the windows, one window 1.5m wide that after numerus visits over the 2 years, has been giving the "all clear" even though no fixings have been used in the bottom edge of the window, meaning that if you push on the window, it flexes significantly. The FENSA and GGF good practice say that this should have at least 2 fixings along its length. They only get one star, as they keep the worst of the rain out.