We manufacture our own sealed units on site, with 28mm units to give optimum insulation. All units are supplied in safety toughened glass where required for Building Regulations. Pilkington K Glass offers improved thermal insulation to save money on your heating bills, with a "U" value of 1.8 - we are always happy to quote with and without K option, but do recommend it if you're planning on using your conservatory all year round. Click here for more details If you're looking for a glass roof we would be pleased to suggest a range of options for you to choose from. Clear toughened glass, Pilkington K glass, Activ coated easy-clean finishes and anti-sun products are all available - just ask for details. If you're looking for solar control products to keep you cool in Summer we recommend Pilkington Activ Blue (ActivBlue DataSheet) and Celsius Glass.