Our range of Cortizo Passive House accredited windows combines cutting-edge technology with exceptional performance. Engineered to the highest standards, these windows are designed to maximize energy efficiency and comfort while minimizing environmental impact. With advanced thermal insulation and airtight construction, Cortizo Passive House windows ensure optimal indoor climate control, reducing heating and cooling costs year-round.
In addition to our Cortizo range, we also offer fully compliant Passive House windows from Rationel. Renowned for their precision engineering and Scandinavian design, Rationel windows meet the strict criteria for Passive House certification. Featuring triple glazing, low U-values, and superior airtightness, Rationel windows deliver outstanding thermal performance and comfort, making them an ideal choice for energy-efficient buildings.
If you have any questions or would like to know more please use the contact form below to get in touch with Keystone.
Keystone Supplies
Unit 17
Storforth Lane Trading Estate
Hasland
Chesterfield
Derbyshire
United Kingdom
S41 0QQ