Oaktree made high quality bifold doors, large feature frames and a number of multi-paned window frames for our garage conversion with attached timber framed garden room, in 2016. We have a listed building, so quality of workmanship was especially important. The care and quality of the work was excellent. The after-sales service has been first class – ensuring that a few double-glazed units (not Oaktree made) that have not survived the warranty period have been promptly replaced. Thank you!