The Alitherm Heritage door and window ranges both feature the slim profiles and sight lines that are associated with traditional steel doors and windows. However, the systems timeless elegance is also accompanied by the outstanding thermal performance of a modern aluminium system – each delivering a `B` Energy Rating. Featuring slim, thermally broekn profiles, Alitherm Heritage windows are available in a number of formats, including fixed panes, sash, top hung and side hung casement, pivot and tilt & turn. these different options may be installed in a combination of horizontal modules, which are stacked using our coupling options to form a multi-part window.