Chris Davies – CMD Architects
Ambitious extension project using Passivhaus principles
An ultra low energy extension has added comfort and space to an 18th Century Cotswolds cottage, using a variety of ‘fabric first’ strategies, including use of Green Building Store’s triple glazed PERFORMANCE timber window and door range.
The extension was designed by Chris Davies of Gloucestershire practice CMD Architects Ltd. Chris commented: “As the project evolved the clients decided that they wanted as near zero carbon an extension as possible , drawing heavily on the detailing and design of the Denby Dale Passivhaus, which we visited during the design stage. So we used many of the same features, for example Teplo Ties in the cavity wall and installing windows within the insulation using plywood boxes and aluminium cavity closers. The extension has been built with its own thermal envelope which is separate from the rest of the house, with external grade doors linking it to the rest of the house, so effectively it is a separate building. The clients now live in the extension most of the time in winter, expanding into the rest of the house when they have visitors or need more space.”
Triple glazed timber windows & doors
Green Building Store’s PERFORMANCE triple glazed timber windows were specified for the project, Chris Davies commented: “The existing building had white painted timber windows, so we needed to match them. For the extension we needed triple glazed units with low U values, that fitted in with the building’s aesthetic and that were not astronomical in price. The PERFORMANCE range fitted the bill and the add-on glazing bars worked well and helped the windows blend in with the aesthetic of the existing building.”
The clients added: “The windows have the advantage of European-style opening for ventilation, but they can also be opened fully internally for ease of cleaning, as well as giving excellent U values. The Lift and Slide door provides a wonderful sense of light and view of the garden, whilst maintaining airtightness. The fenestration as a whole suits the appearance of both the old and new parts of the buildings, with the large sliding door justifying its wall of glass looking over the beautiful view.”