Where Design,
Performance &
Precision Meet
OUR BACKGROUND & APPROACH
Built on Experience.
Focused on Design-Led Projects.
Optitherm is the next step in the evolution of NKG Composite, created to better reflect the quality of our offering and the level of projects we work on today. We supply premium window and door systems for high-end residential, renovation and selected commercial schemes, working closely with architects, builders, self-build clients and developers.
Our approach is centred on providing the right products for each project, ensuring they align with the architectural vision while delivering strong thermal performance, durability and long-term reliability. From initial enquiry through to completion, we aim to offer a straightforward, professional and supportive service, helping clients make informed decisions at every stage.
Survey & Understanding
Accurate site surveys and early-stage discussions to fully understand the design intent and project requirements.
Specification & Design
Careful system selection to ensure the right balance of aesthetics, performance and long-term reliability.
Project Delivery
Expert delivery and installation, completed with precision and attention to detail from start to finish.
OUR SERVICES
High-performance window systems designed to complement the architecture of each project. Suitable for both contemporary and traditional schemes, with a focus on thermal efficiency, durability and long-term reliability
Window Systems
Door Systems
From large-format sliding doors to bifold and entrance systems, our doors are selected to maximise light, space and connection, while delivering strong performance, security and smooth operation.
OUR SYSTEM PARTNERS
Premium systems carefully selected for design-led projects,
exceptional performance and long-term reliability.
OUR PROJECTS
Recent Projects
Woodlands
Contemporary new-build featuring VELFAC glazing, bespoke gable windows and large-format glazed elevations designed to maximise natural light.
Architect-designed home combining expansive glazing, slim sightlines and panoramic views across the surrounding landscape.
Cloud Lodge
Premium residential project featuring facetted VELFAC frames carefully engineered to create a curved glazed elevation while maintaining clean architectural lines.
Fennyland
HOMEOWNER, WORCESTER
"We cannot thank Optitherm enough for helping us bring our vision for our back-to-brick renovation and extension to life. Beth was knowledgeable, patient, and supportive throughout, helping us make the right choices for our project. We absolutely love our VELFAC windows and couldn't be happier with both the product and the service we received."
LOUISE WOOD &
MATTHEW HUXFORD
GET IN TOUCH
Start Your Project
Speak to us about your plans and we’ll guide you through the next steps.