Welcome to Lakeview Home Improvements uPVC Doors At Lakeview Home Improvements, we’re delighted to provide our Coventry customers with top-quality uPVC doors. Combining cost-effectiveness with high performance, our uPVC doors are a popular choice for homeowners seeking a low-maintenance, energy-efficient solution. What are uPVC Doors? uPVC, or unplasticised Polyvinyl Chloride, is a type of plastic that’s robust, resistant to weathering, and excellent at retaining heat. These properties make it an ideal material for exterior doors.