Whilst we’ve been repairing the frames, our joiner has built the replacement sash windows, replicating the originals exactly in terms of visible profile detail. I’ve had the box frames and sashes all sprayed utilising a micro-porous paint system than enables the joinery to breath, expand and contract without (hopefully) damage. The glass is to be ultra-slim double glazed units http://www.slimliteglass.co.uk/advantages.html