NJS Sash Windows is a trusted sash window company specialising in sash window renovation, restoration and repair across Stamford, Peterborough, Cambridge and London. As experienced timber sash window specialists, we restore period and listed properties, including Grade II & Grade II listed buildings*. From sash cord replacement, spiral balance repair, and draught proofing to complete timber sash window renovation, we help preserve the character of traditional windows while improving performance. If you are looking for one of the best sash... read full review »