About Us – Keystone Supplies

About Keystone Specialist Glazing Systems

Founded by experienced tradespeople with roots in hands on construction, Keystone delivers architectural glazing systems tailored to ambitious renovations, extensions, and bespoke new builds. Combining deep practical site experience with premier European manufacturer partnerships, we supply and support market leading composite, aluminium, and timber alternative solutions across the United Kingdom.

Nationwide Reach With Local Expertise

Operating from our central facility in Chesterfield, Keystone works closely with self builders, architects, interior designers, and commercial contractors nationwide. Our curated portfolio unites the finest architectural systems on the market, from ultra slim Spanish aluminium and authentic British steel look profiles to high efficiency Danish composites. Backed by specialist advice from tradespeople who understand site tolerances and structural integration, we make certain every system delivers flawless performance and long lasting architectural beauty.

Our History

Keystone began directly on active building sites. Specializing in complete structural barn conversions, our early trade work spanned traditional stonework, blockwork, complex timber roofing, and fine joinery. Facing continuous challenges sourcing dependable, high specification timber windows, we forged direct relationships with premier manufacturers to secure better solutions for our projects.

Over thirteen years ago, that hands on experience led to the founding of Keystone. What started with specialist timber joinery quickly expanded into trusted partnerships with pioneering brands including VELFAC, Rationel, Cortizo, Evolution, and ALUCO. Because our foundation is built on practical construction rather than just sales, our team brings genuine technical insight, structural understanding, and trade tested knowledge to every glazing project.

Trusted By You

As an independent business, we are dedicated to the supply and installation of beautiful, bespoke windows and doors. What's more, we strive to support our customers, from our showroom to your door, you'll be able to contact us every step of the way.
Our client testimonials speak for themselves.

Keystone Supplies Window Company has been an absolute pleasure to work with! From start to finish, their professionalism and attention to detail stood out.

Jenny B

An excellent install by Keystone of large aluminium sliding doors. They look great and install was slick. I would recommend

Jon D

Kevin and his team at keystone were an absolute class act to work with. Outstanding, incredibly precise work on some beautiful contemporary Velfac sliding doors and windows. Exemplary customer service. Many thanks

Tom L