Heritage Aluminium Windows
Slimline, Energy-Efficient Windows for Period & Listed Properties
At Marlin we specialise in designing and manufacturing heritage windows at our premises in Keighley, West Yorkshire. If you’re looking for the highest quality aluminium heritage window glazing available in the UK, we have two systems available:
- Alitherm Heritage Windows – ideal for listed buildings and conservation areas
- Classic Heritage Windows – more commonly fitted in modern properties seeking a classic look
Whichever system is the most suitable for your project, aluminium heritage windows provide sleek, traditional styling with modern thermal performance and solid security at a fraction of the cost of steel.
Explore our Heritage Aluminium Windows
Heritage-style aluminium windows offer very slim sightlines that maximise natural light and are available in designs that equally suit period and contemporary properties. Here’s a little more information about our heritage window ranges:
Alitherm Heritage Windows
Ideal for: Listed buildings, conservation areas, Art Deco properties, stone mullion openings, and new properties seeking a traditional style.
Our Alitherm Heritage windows have slim frames and are manufactured to replicate traditional steel windows, while offering modern thermal performance. They are approved for listed building replacements by many council authorities and are ideal where like-for-like replacements are required.
Featuring polyamide thermal break technology, our Alitherm Heritage windows can provide a U-value of 1.5 W/m²K double glazed, with a Window Energy Rating (WER) of B. U-values of 1.4 and 1.2 W/m²K are possible with certain 28mm triple-glazing option and they have a high-quality powder-coated paint finish that is guaranteed for 25 years. All Heritage windows have high security multi point locking fitted as standard and manufacturing quality is backed by our 10-year warranty.
Classic Heritage Windows
Ideal for: Modern renovations, extensions, period homes and commercial refurbishments.
Slim frames and the Thermlock® thermal break, with double or triple glazing options, provide cutting-edge thermal performance, a timeless look and a cost-effective route to PAS 24 security.
The Classic range also allows light to flood into your property. These slim, handmade windows create airy, light-filled interiors that enhance your space and add to its sense of serenity. It is a popular thermally efficient choice for replicating steel windows from a bygone era or recreating Art Deco looks with bars fitted either horizontally, vertically or both.
Ready to talk to us?
Request a quote or call 01535 603909
Our Heritage Aluminium Windows in a Nutshell
Not sure which range fits your project? Here are the two systems side by side. Speak to our team if you’d like help choosing.
| WINDOW SYSTEM | Alitherm Heritage | Sheerline Classic |
|---|---|---|
| Appearance | Steel window replacement | Modern heritage aluminium |
| Authenticity compared to steel look | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ |
| Typical Use | Listed & conservation | Refurbishment, replacement & new builds |
| Frame depth | 47 mm | 64 mm |
| Fixed light sightline | 33 mm | 48 mm |
| Sash sightline | 58 mm | 60.5 mm |
| Max size – fixed pane | W 2100 mm × H 2100 mm | W 1500 mm × H 2100 mm |
| Max size – side hung | W 700 mm × H 1400 mm | W 710 mm × H 1450 mm |
| Max size – top hung | W 1400 mm × H 1400 mm | W 1300 mm × H 1225 mm |
| Tilt & turn | Available | Unavailable |
| Max size tilt & turn | W 1200 mm × H 2100 mm | Unavailable |
| Glazing thickness double glazed | 28 mm | 28 mm |
| Glazing thickness triple glazed | 28 mm | 28 mm |
| Overall U value double glazed | 1.5 W/m²K | 1.4 W/m²K |
| Overall U value triple glazed Argon | 1.4 W/m²K | 1.4 W/m²K |
| Overall U value triple glazed Krypton | 1.2 W/m²K | 1.2 W/m²K |
| Laminated Glass External Pane | Contact Us | Contact Us |
| Part Q PAS24 Security | Optional upgrade | Standard with optional laminated glass |
| Part L compliant | Yes | Yes |
| Part F compliant | Yes | Yes |
| Weather testing | BS6375 tested | BS6375 tested |
| Listed Building Suitability | Excellent | Good |
| Thermal Efficiency | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ |
| Best For Strict Conservation | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ |
Why Choose Our Heritage-Style Aluminium Windows?
Steel Look Without the Cost
Our products offer top quality manufacturing and faithfully replicate traditional steel frames, at a fraction of the cost of steel.
Ultra-Slim Sightlines
Our Alitherm windows are particularly suitable for stone mullion applications, and our Classic range offers a slightly deeper frame profile more suitable for replacement applications, but equally maximising glass area and natural light.
Low Maintenance
Our aluminium windows are rust and rot-proof, requiring far less upkeep than timber or steel as they are protected with a polyester powder coated paint finish that is guaranteed for 25 years.
Longevity
With relatively low maintenance, aluminium windows can provide high quality performance for over 30 years.
Sustainability
All of our heritage windows and doors are made from endlessly recyclable aluminium – the amount of energy used to reprocess aluminium is only 5% of what is required for primary manufacture. Aluminium windows are therefore durable and sustainable choices for heritage windows.
Thermal Performance
Both ranges offer classic styling with the latest thermal technology, keeping your property cosy and heating costs down.
Security
With multi-point locking on both ranges and PAS24 Secured by Design accreditation on the Classic range, heritage styling doesn’t need to compromise the security of your property.
Why Choose Marlin Windows?
Heritage glazing is our specialist area. We’re a family-run Yorkshire business and one of the UK’s most experienced manufacturers of premium aluminium heritage products.
Reasons why you should expect 100% satisfaction.
Quality Control
We believe our quality standards are unrivalled. With a background in aerospace engineering, our manufacturing processes are monitored with well-defined quality controls, and inspections are performed by trained personnel.
Care
We respect you, your property and your project, taking care over every detail from order through to delivery and post-installation.
We provide a FREE sample service to assist with surveying decisions, design considerations, or planning applications – just pick up the phone and ask.
Project Focus
We make every window to your exact made-to-measure specifications, with standard and bespoke sizes available.
Experienced across diverse property types, from listed buildings and period homes to contemporary commercial premises.
If you’d like to see our products up close before you buy, come along to our Keighley showroom. You can visit by appointment Monday to Friday 9am to 4:30pm, Saturday 8am to 12 noon, or by special arrangement outside of these times. Give us a call on 01535 603909 to book.
Alternatively, get in touch with us online to get a quote or discuss your needs.
Latest projects
HERITAGE WINDOWS AND DOORS
Alitherm Heritage Windows and Doors – Leeds
STEEL REPLACEMENT WINDOWS
Listed Farmhouse, Heritage Windows and Doors – Skipton
HERITAGE WINDOWS AND DOORS
Batt House, Northumberland Alitherm Heritage Windows and Doors
The grasp of the importance of design and quality of manufacture from the Marlin Team is second to none”.
VIEW THIS CONSERVATION AREA PROJECT
FAQs About Heritage Aluminium Windows
What's the difference between your two heritage window ranges?
Alitherm is designed for listed buildings and conservation areas, though it’s still a popular choice for modern properties. Classic suits period renovations as well as new-builds seeking a heritage style.
Can heritage aluminium windows be used in listed buildings?
Absolutely, Alitherm is your best bet here as it’s approved by many council authorities as a like-for-like replacement for steel windows. We recommend that you consult your particular authority about the specific requirements for your area, then we can provide advice on the most appropriate product.
Do I need planning permission to replace my windows?
If you live in a listed building or in a conservation area you’ll probably need approval, and permitted development rights apply for other properties in some cases. We can advise you on the best product to support your application.
How energy efficient are heritage aluminium windows?
Both our ranges exceed Part L of the Building Regulations and the Classic range has triple-glazing options for even greater insulation.
How much do heritage aluminium windows cost?
Cost depends on size, style, glazing, colour and installation options. Get in touch for a quote and we’ll do our best to get back to you within 24 hours (quotes for large projects may take a little longer). Please note, we have interest-free financing available.
How long do they last, and what warranty do you offer?
Well-made aluminium windows can last more than 30 years, and both our heritage ranges carry 10-year manufacturer’s warranties, as well as 25-year paint guarantees.
Do they need much maintenance?
They need very little maintenance – much less than timber or steel. Aluminium is naturally corrosion-resistant and doesn’t rot or rust.
Do you offer installation?
Yes, our installation team operates across West Yorkshire, South Yorkshire, Greater Manchester, Merseyside, Lancashire, Derbyshire, Nottinghamshire, East Riding and Cheshire. If you’re outside this area, please get in touch as we may still be able to help.
