Founded in 1996, the company has grown from a local start-up into a trusted name in PVC and glass fabrication, supplying an estimated 117,000 windows and over 6,000 doors to more than 15,000 customers across Scotland and beyond.

Over 7,828 working days, Williams Windows has navigated major shifts in construction standards, energy efficiency requirements, and manufacturing technology, while remaining firmly rooted in Clydebank.

“Thirty years ago, three Williams set out to build a business based on quality, reliability and local trust,” said Fraser Sinclair, managing director. “Reaching this milestone — and seeing the number of homes and businesses we’ve helped improve — is a huge source of pride for our entire team. We’re incredibly grateful to our staff and the customers who’ve supported us since 1996.”

In recent years, the business has invested heavily in modernisation, including the transition to digital accounting systems, a full replacement of its vehicle fleet, progress towards net-zero operations, and the completion of its first Modern Apprenticeship. The company is on track to achieve record turnover in the 2025/26 financial year, underlining continued demand for locally manufactured products.