I’ve used Metrotile https://www.metrotile.co.uk/bu....ilding-types/extensi systems for several home extensions and always point clients to this page. It clearly explains the benefits — especially the low weight and 40-year weatherproof guarantee. Traditional flat roofs on extensions often cause leaks, but the pitched Metrotile solution solves that problem. Installation is quick, the tiles look great, and customers appreciate the durability.