We have a period farmhouse and needed to replace the old single glazed wooden sash windows. Derwent installed Bygone collection UPVC sash windows for us and we are really, really impressed with the windows. The proportions ensure that they look wooden and are in keeping with the property. The compliments from visitors have already started and people are surprised to find they are UPVC. Andy and the team were super. Hard working and also tidy workers, something I have learnt is not common place with workmen! The quality of the finish is very impressive, thank you!