New air testing rules require the elimination of drafts completely. A cold non-vented roof space using breather membranes can be up to 25% more energy efficient than the traditional vented roof space. This means that a cold non-vented roof is now an important design element. Forthcoming regulations will also insist that the thermal bridge, which occurs over the wall plate at eaves level, is addressed and this is best achieved again using the cold non-vented system. Areas serviced: West Dorset & Yeovilwww.permavent.co.uk228 Portland Port Business Centre Castletown, DT5 1PA