Since 1976, Sierra Windows has grown into one of the UK's leading windows and doors suppliers, specialising in supplying PVCU windows and doors across the UK. Whether you're looking for energy efficiency, sustainability, bespoke custom designs or just great service, we at Sierra will provide for all your needs. Sierra is part of the renowned and highly respected Epwin Group, an independent thriving British business and an expert manufacturer and supplier of PVCU home improvement products. All our home improvement products are rigorously tested during the manufacturing process to ensure compliance to all industry regulations, but the level of quality doesn't stop there. Our ordering system has three separate levels of accuracy checking, and our deliveries are 99.1% on time and complete.