Keystone Windows & Doors

Transform your home with bespoke, high performance window and door solutions supplied and installed by Keystone. From energy efficient triple glazing to architectural aluminium and handcrafted timber, we deliver market leading security, acoustic insulation, and thermal performance tailored to your exact property specifications.

Request a quote

Learn about us

Evolution's Timber Effect Windows & Doors

Authentically replicating the classic look of traditional wooden windows without the constant need for maintenance. Evolution windows provide hight-performance efficiency and security while preserving a historical aesthetic.

Find out about evolution

VELFAC Composite Windows & Doors

Experience world class Scandinavian design with VELFAC composite glazing systems. Featuring ultra slim 54mm profiles, low maintenance aluminium exteriors, and warm internal timber frames, VELFAC brings unrivaled natural light, uniform sightlines, and modern thermal efficiency to both contemporary builds and traditional home refurbishments.

Learn more about Velfac

CORTIZO's Aluminium Windows & Doors

Maximize your living space with Cortizo’s industry leading architectural aluminium doors and windows. Engineered with minimal sightlines, thermal break technology, and PAS 24 certified multi-point locking arrays. Cortizo systems create seamless transitions between indoor and outdoor environments without compromising on structural integrity or thermal comfort.

Helpful information about Cortizo

ALUCO Steel-Look Windows & Doors

The definitive industrial aesthetic combined with modern aluminium performance. ALUCO systems maximize natural light and offer the iconic, minimalist appearance of steel, creating sleek, elegant spaces.

Learn more about ALUCO

Endlessly customisable Timber Windows

From traditional sliding sash windows to authentic casements, every timber frame we build is tailored to your exact specifications. Explore limitless design freedom with sustainably sourced engineered hardwoods and pure timber, bespoke heritage colour palettes, custom glazing bar arrangements, and quality forged ironmongery. Experience the tactile quality, smooth operation, and exceptional joinery standards first hand by exploring the collection in our dedicated showroom.

Triple Glazed Windows

All of our products are compatible with the latest triple glazing systems, allowing you to add a third pane of glass and an extra insulating gas cavity, lowering U-values significantly, cutting heating bills, eliminating cold spots, and reducing external noise pollution.

Achieve ultimate thermal performance and home comfort with our efficient triple glazed windows. Designed to lock heat inside during winter and prevent overheating in summer, triple glazing excels in thermal insulation while also providing superior noise dampening and high security. Triple glazing is the ultimate longterm investment for low energy and Passivhaus standard homes.

Timber, Aluminium & Composite Doors

Front doors, sliding doors, bi-fold doors, internal doors, steel doors, and much more—Keystone offers a comprehensive collection of bespoke entry and patio systems built to elevate your entire property. Whether you require the ultra-slim panoramic views of aluminium sliding doors, the robust security of high-density composite entrance doors, or the timeless elegance of solid timber, every door is custom-engineered to deliver effortless operation, high thermal resistance, and maximum home security.

Have an exciting project and need advice?

Having an extensive background in construction, we understand how stressful these projects can be. Between styles, efficiency and legislation, getting new windows can be a headache.

If you need support with our range of windows, please get in touch with us today to find out which windows will work for you!

Created by Nature, Perfected by Craftsmen

Founded in 2013 by experienced builders, Keystone Specialist Glazing Systems was born out of a passion for high quality joinery and real world construction expertise. Having started on site with stonework, roofing, and barn conversions, we know exactly what it takes to bring demanding architectural projects to life.

Today, based out of our Chesterfield showroom, we supply and install market leading timber, aluminium, and composite windows and doors from trusted brands like VELFAC, Rationel, and Cortizo. Whether you are working on a period restoration, a self-build extension, or a modern Passive House, trust a team that knows glazing from the ground up.

Opening Times

Monday - Friday

09:00 - 16:00

Saturday

By Appointment Only

Sunday

Closed

Please note that we are also able to open later to offer you a personal, one to one service upon request. Please give us a call to arrange a time that fits you. Our showrooms are situated at Storforth Lane Trading Estate in Hasland, Chesterfield.

What our Customers Say About our Products

4.3

Libby

Manchester

Simple, effective service…. very professional, arrived on time, excellent price

Linda

Leicestershire

We were overly impressed with the quality and design of the Keystone-Supplies product range, every detail was perfectly finished, it really has changed our home

Richard

Derbyshire

I would strongly recommend these products to anyone, from the windows to the wooden flooring every minor detail is seen too with an attentive eye – perfect design and style