Glass Extensions & Wintergardens
We create precision-engineered glass extensions and Wintergardens that transform homes into light-filled, thermally efficient living environments. Designed for year-round comfort, they provide refreshing ventilation in summer and consistent warmth throughout winter. Each insulated aluminium or timber-aluminium system is custom-built in Germany, offering expansive garden access alongside advanced glazing, ventilation, shading, and automation features.
Sliding Glass & Balcony Glazing
When you choose Spectrum, you invest in proven knowledge, technical expertise and extensive experience. As a Gold Level Internorm 1st Window Partner and a Solarlux Quality Partner, we deliver advanced sliding glass and balcony glazing solutions. Our uninsulated systems are ideal for glass rooms, canopies, partitions and balconies, including the versatile SL20 linear sliding and SL25 slide-and-turn configurations.
Sliding Glass Doors
We supply high-performance, low-energy sliding glass doors achieving U-values as low as 0.79 for Passivhaus standards. Our range features premium glazing systems from Germany and Austria, installed by highly skilled teams to ensure exceptional results. Clients may select from lift-and-slide, ultra-minimal profile, or slimline aluminium designs, each built to exacting specifications. With durable external aluminium finishes and a choice of internal timber or UPVC, every door is crafted to deliver lasting quality, refined aesthetics, and outstanding thermal efficiency.
Solarlux Bifold Doors
We supply Solarlux bifold doors, bespoke premium systems manufactured to order in Germany and engineered to redefine the relationship between indoor and outdoor living. As the originators of the modern bifold door, Solarlux continue to set industry standards through innovation, precision engineering and rigorous independent testing. Every door is fully constructed in Germany, thermally broken throughout, security tested to European standards, and built for enduring performance. Although positioned at the higher end of the market, we firmly believe these class-leading doors represent outstanding long-term value.
Internorm Entrance Doors
We provide Internorm Entrance Doors that unite exceptional craftsmanship with advanced security and outstanding thermal performance, achieving U-values as low as 0.64 for Passivhaus standards. As an elite Gold Level 1st Window Partner, we combine Internorms renowned engineering with our expertise to deliver truly bespoke designs. Each door is individually crafted in aluminium or timber/aluminium, tailored precisely to your vision. Our team will guide you through every option to ensure a distinctive and impressive entrance.
Kastrup Windows
We proudly supply Kastrup timber/aluminium windows and doors, bespoke crafted in Denmark to deliver exceptional performance, refined design and lasting quality. Combining Scandinavian craftsmanship with advanced energy efficiency, our windows achieve Uw values as low as 0.76 and provide impressive acoustic insulation. Aluminium external cladding ensures minimal maintenance, while the internal timber finish offers versatile staining or factory-painted options to complement any architectural style.
Passive House Windows
We supply high-performance timber and aluminium composite Passive House windows from Internorm, achieving U-values as low as 0.6 and meeting the stringent Passivhaus requirement of 0.8 W/(mK) or better. As a Gold Level 1st Window Partner, we combine expert knowledge with precise installation carried out by fully trained teams. Our range includes both certified and non-certified solutions, together with lift and slide doors specified to Passive House standards, ensuring exceptional thermal performance and effective solar management.
Internorm Windows
We supply and install Internorms premium, low-energy windows, crafted in Austria to exacting standards. Each unit is made to order, combining aluminium exteriors with timber or high-grade uPVC interiors and triple glazing as standard. As Gold-level Internorm 1st Window Partners with over 13 years experience, we deliver unrivalled expertise and service. We ensure precision through rigorous quality checks.
Sep 21, 2025
Quality product that was installed by a professional team.
This is the second house that I have had Spectrum manufacture and install windows in, I wouldnt go anywhere else for windows and doors ever again.
Will add photos later as the house is still under renovation
Sep 03, 2025
Delighted with my Winter Garden supplied and fitted by Spectrum . They worked flexibly with my builder who was very impressed by the quality and expertise . I had a minor problem with a lock 14 mths or so later which was sorted promptly . I wouldnt hesitated to recommend them .true professionals
Sep 01, 2025
The sales team were friendly and professional and I was fully informed about the product and pricing. Neil and the survey team are exceptional. All the fitters, a shout out to Lea and Jack, what an experienced bunch. The team have transformed my house. It's beautiful and amazing. Plus has added value to my property. I would highly recommend Spectrum to everyone!
Aug 05, 2025
Spectrum have recently installed a replacement window (Internorm KF410) for our vaulted bedroom and I'm very happy with the result and the process. Everyone I dealt with, from sales, survey to fitting was extremely knowledgeable and helpful. It was a tricky project with numerous issues I knew needed overcoming, and a few I hadn't been aware of, but the installers worked through all of them and the outcome was everything I could have hoped for. I will be calling on them again to replace the rest of the windows and doors.
Jan 07, 2025
What a great company to deal with. Our original supplier of Kastrup windows went into liquidation and we have been struggling with support to fix some minor issues. Dave from the service team has helped us to get them sorted very quickly and efficiently!
Nov 01, 2023
What an amazing Company. Our property has a unique two-story glass frontage, that was originally oak framed. The oak frame was severely weathered, rotting in places and looked old and tired. We had the idea of replacing these with modern aluminium frames, and to also replace all the other doors and windows of the property, to give a more contemporary appearance. This would involve ripping out an entire two-storey wall of our property, so we were naturally apprehensive. After a lot of research on-line, we found Spectrum. We arranged a visit to their showroom, where we met Dave from Sales, who carefully explained the pros and cons of different products. We selected Internorm as the best solution for our needs. Over the next few weeks Dave and the team worked with us, helping to select colours, style, and providing life-like mock-up drawings. Once the design was settled, Spectrum carried out a detailed survey, measuring everything with exceptional precision. After the frames and panels had been manufactured by Internorm, the installation schedule was agreed. The Installation team were phenomenal. Led by Mark, their level of professionalism, tidiness and attention to detail were exceptional. The installation went according to plan but as with any major construction project there were a few unseen snags and problems. Every snag and problem were identified and efficiently resolved. We now have a stunning property, with an amazing contemporary look, and windows that will last a lifetime. A big mention must go to Lone who did a phenomenal job making all of this happen. God bless you Spectrum, you are a very special company. Highly Recommended.
Feb 15, 2023
Just had 3 Internorm windows fitted - excellent sales service as we went back and forth a few times amending specs and the fitters were excellent. Really pleased with the result, I never knew how much joy a solar powered integral blind would give me!! We are looking at phase 2. Would highly recommend, friendly and professional service.
Oct 18, 2022
What can we say about Spectrum?
After a good few months of following them on social media and reading all the comments written by previous customers, we decided to take the plunge and visit their showroom. We needed good strong large sliding doors and windows for our barn that not only looked good but did a great job of keeping the weather out too as we live on top of a very windy hill in the Peak District.
From the moment we walked through the showroom door Dave was so helpful. After showing us around, he sat us down made us a coffee and chatted to us about what we were looking for. There was no hard sell, no pressure just a genuine interest in what we wanted to achieve. He was very knowledgeable and informative from the start and helped us come to the right decision on what windows and colours to choose. Our interactions with him both by visits, phone calls and emails lasted at least a couple of years before we were finally able to put our order in, mainly due to the outbreak of Covid. During this time Dave kept in touch with us throughout and was always very patient, polite and pleasant with us. By the end of lockdown and the whole process, we felt we had made a friend .
The whole team at Spectrum are excellent at their jobs, from Silje who came to measure up and advised us in preparation for the fitting, to the fitters who worked tirelessly through some really awful winter weather. These guys are a credit to the company!
We are so pleased that we chose Spectrum, we love our windows and everyone who has either worked on our barn since or has come to visit to see where we are up to, have all commented on how well made and nice they are!
Thank you so much for helping us create our dream home, we had such a good experience with your company and would recommend you to our friends and family in a heartbeat . Will send photos when the barn is finished.
Kindest Regards
John & Shirley Winterbottom
Jul 21, 2022
Spectrum supplied and fitted internorm windows to a self build I carried out in Sheffield and I cannot recommend them highly enough. The windows are worth every penny. The quality is as good as promised. Every tradesman working on the project has commented on the look and the quality being better than anything theyve seen before. Spectrum themselves were brilliant. Neil and Dave helped all the way through buying and after sales. The fitting team were professional, diligent and cared about the job. Simply put they were the best tradesmen Ive had on site during the entire 16 month build. Worth every penny from start to finish and wouldnt look elsewhere if I carried out another project.
Jul 17, 2022
Treat yourself.lifes too short
I like good design, quality, value for money and good customer service.
And when it comes to spending my hard earned cash I fear that I will be let down and that these standards wont be met; fear not with Spectrum - weve now finished having the floor laid and moved the furniture in and can say we love it and are the envy of our neighbours. All the tradesmen, friends and neighbours have been so impressed that they have asked for details for their own properties.
Okay its not cheap but perhaps thats the point - the winter garden exudes quality and is our grand design.
Neil is honest, warm and a friendly gent - he knows his product and business and enthusiastically guided us through the process..before we knew it we had made a big investment and were dreaming of our new room.
The whole fitting team led by Lee did not let us down and were equally as capable and knowledgable.
A great company to work with who were as passionate as we were to get the dream build.
Apr 26, 2021
Super high quality windows, and a team that strive for perfection. From meeting Neil who followed the project through , the experience was fantastic.
Highly recommended. Please contact me for any further info.