Heritage Aluminium Windows for Contemporary Homes
Slimline Heritage Windows for Modern Homes
Alitherm Heritage windows bring the slim sightlines and industrial character of traditional steel windows to contemporary homes, new builds and modern extensions. Made from thermally broken aluminium, they combine timeless steel-look styling with modern energy efficiency, security and low maintenance.
Whether you’re designing an architect-led new build, adding a contemporary extension or replacing bulky existing windows, Alitherm Heritage gives you the distinctive look of steel without the cost and upkeep.
✔ Typical 4-week lead time for supply only
✔ Nationwide supply & delivery
✔ Regional survey & installation
✔ Interest-free credit available – T&Cs apply
✔ 10-year manufacturer warranty
✔ 25-year paint finish guarantee
✔ Made to measure
✔ Yorkshire made since 2003
Which Heritage Window Is Right for You?
Alitherm Heritage is our original steel-look aluminium window system, commonly chosen for heritage properties but equally suited to contemporary homes and new builds where slim sightlines and maximum natural light are a priority.
For projects requiring enhanced thermal performance, Alitherm Heritage 60 offers an upgraded specification. Sheerline Classic brings distinctive stepped Art Deco detailing, while our AluSpace internal range creates matching steel-look screens and partitions for contemporary interiors.
Explore our full Heritage collection to compare the different systems, frame styles and finishes.
What Are Alitherm Heritage Windows for Contemporary Properties?
Alitherm Heritage is a slimline aluminium window system designed to recreate the elegant proportions of traditional steel windows, with the benefits of modern aluminium construction.
Although originally inspired by period steel glazing, its clean lines and distinctive glazing bars make it equally suited to contemporary architecture. It’s particularly effective in modern extensions, architect-designed new builds and industrial-inspired homes where the windows are an important part of the overall design.
With authentic glazing bar options, a wide choice of colours and a U-value of 1.5 W/m²K with specified double glazing, Alitherm Heritage combines traditional steel-look detailing with modern thermal performance.
Every window is made to measure, allowing you to create a design that complements your property rather than working around standard sizes.
Key Features
Ultra-Slim Steel-Look Profiles – Authentic glazing bars, transoms and mullions for a distinctive architectural finish.
47mm Frame Depth with 33mm Sightline – Slim aluminium frames designed to maximise natural light.
Modern Thermal Performance – U-value 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 options, fully compliant with the June 2022 Document L UK building regulations
28mm Glazing – Gasket-glazed units with a choice of glazing specifications.
High-Security Multipoint Locking – Secure locking systems for added peace of mind.
Flexible Configurations – Fixed, side-hung and top-hung outward-opening windows.
Wide Choice of Finishes – Single or dual-colour powder coating, including bespoke colours.
Rust-Proof Aluminium – Durable, low-maintenance frames that won’t rust or need regular repainting.
10-Year Manufacturer Warranty – Plus a 25-year paint finish guarantee.
Made to Measure – Manufactured to your project’s individual requirements.
Why Choose Heritage Windows for a Contemporary Home?
Heritage windows bring timeless steel-look styling to modern homes, new builds and extensions. Their slim frames and distinctive glazing bars complement brick, render, timber and contemporary architecture.
Authentic Heritage Styling – Classic slimline profiles without the cost and upkeep of traditional steel.
More Natural Light – Slim aluminium frames maximise glass and natural light.
Energy Efficient – Thermal breaks and high-performance glazing help retain warmth.
Low Maintenance – Rust-proof aluminium with a durable powder-coated finish.
Flexible Designs – Choose traditional glazing bars or simpler contemporary styles.
Designed for New Builds, Extensions and Modern Living
Alitherm Heritage windows are a versatile choice for contemporary projects where appearance matters just as much as performance.
They’re particularly suited to:
Architect-Designed New Builds – Add character and distinctive Heritage styling to modern homes.
Contemporary Extensions – Create a seamless connection between traditional properties and modern additions.
Open-Plan Living Spaces – Slim aluminium frames maximise natural light and create a spacious feel.
Industrial-Inspired Homes – Heritage glazing bars complement exposed brick, concrete, timber and modern interiors.
Window Replacement Projects – Replace bulky uPVC windows with slimmer, more elegant aluminium frames.
Whether you prefer bold black frames or a softer colour that blends with the building, we’ll manufacture your windows to suit the design.
Contemporary SIP New Build
‘We used Marlin for windows and steel style doors and internal screens using Alitherm Heritage products on our recent self build project. Marlin are not local to us but provided an excellent service from quotation, advice, redesigns and with very detailed comms throughout. The windows and doors are the talking point of our entire build. Adrian from Marlin said that windows become the eyes of the house and I didn’t forget that – our eyes are simply stunning. Would highly recommend’.
Gareth Robinson
Why Homeowners Choose Marlin
As a family-run manufacturer based in Keighley, West Yorkshire, we’ve been making aluminium windows and doors since 2003.
We combine specialist knowledge of Heritage glazing systems with made-to-measure manufacturing, practical advice and personal service from initial enquiry through to delivery or installation.
Whether you’re working with an architect, managing a self-build or upgrading your existing home, we’ll help you choose windows that look right and perform as they should.
“That is the service you want from a supplier, and it is why we are ordering the last piece of the house from them too. Highly recommended.”
— Per & Lisa Vögerl
★★★★★ 5-star customer review VIEW THE PROJECT
Supply & Installation Options
Choose professional installation across our regional service area or nationwide supply-only delivery.
Supply & Install
Our experienced teams provide professional surveying and installation across West Yorkshire, South Yorkshire, Greater Manchester, Merseyside, Lancashire, Derbyshire, Nottinghamshire, East Riding of Yorkshire and Cheshire.
Supply Only – Nationwide
Every window is made to measure at our Yorkshire manufacturing facility and can be delivered nationwide, ready for installation by your builder or chosen contractor.
Outside our installation area? We can still supply and deliver your windows anywhere in the UK.
Visit Our Keighley Showroom
See the difference slim sightlines can make before you decide.
At our showroom in Keighley, West Yorkshire, you can compare Alitherm Heritage with our other steel-look aluminium window and door systems, explore glazing bar arrangements and finishes, and speak to our team about your project.
We have one of the UK’s largest selections of Heritage steel-look windows and doors on display.
Showroom visits by appointment:
Monday to Friday: 9am–4:30pm
Saturday: 8am–12 noon
Other times by special arrangement.
Call 01535 603909 to arrange your visit.
Alitherm Heritage Windows for Period Properties
A proven choice for steel replacement, heritage, listed, retro refurbishment and Art Deco projects.
- Iconic slim aesthetics with authentic transoms and mullions.
- Flexible configuration options, including fixed, sidehung and tophung.
- Wide choice of finishes to complement traditional architecture.
COLOURS AND GLAZING
Our aluminium profiles are polyester powder coated by our systems suppliers using the very latest paint application techniques guaranteed for 25 years.
Fully compliant to the latest June 2022 building regulations our standard double glazing is the exceptional light transmitting, energy saving ClimaGuard® A+ low emissivity (Low-E) glass manufactured by Guardian Glass.
Latest projects
HERITAGE WINDOWS
North Rigton, New Build – Aluminium Glazing
CONTEMPORARY WINDOWS
Heritage Windows in Contemporary Setting – Wilmslow, Manchester
HERITAGE WINDOWS AND DOORS
Batt House, Northumberland Alitherm Heritage Windows and Doors
Ready to transform your home?
Get a made-to-measure quote for your contemporary project today. Our team will guide you through sizes, styles and glazing options to find the perfect fit for your home.
Or call us on 01535 603909 to speak with our team.
Frequently Asked Questions
If you require any support, please don’t hesitate to review our FAQs below or drop us a message on our contact form here
What are Alitherm Heritage windows?
Alitherm Heritage windows are ultra-slim aluminium windows designed to replicate the appearance of traditional steel frames while delivering modern thermal efficiency, security, and durability. They are ideal for homeowners who want a heritage aesthetic with contemporary performance.
Are heritage-style windows suitable for modern homes?
Yes. Although originally designed for period properties, Alitherm Heritage windows are increasingly used in contemporary homes where slim sightlines, large glass areas, and industrial-style aesthetics are desired.
What information must be provided in order to get an accurate quotation?
We will ask you to provide the following information:
- Approximate dimensions (width x height)
- Basic design/layout
- Project location
How long will my quotation take?
We aim to return all quotations within 24 hours however large projects may take longer.
What makes these windows ideal for contemporary properties?
Their narrow frames maximise natural light and create clean architectural lines, complementing modern extensions, self-builds, and minimalist designs. Despite the traditional look, they meet current building regulations for energy performance.
Are aluminium heritage windows energy efficient?
Yes. Thermally broken aluminium frames combined with high-performance glazing help reduce heat loss and improve energy efficiency, achieving strong performance ratings when specified correctly.
- Window Energy Rating ‘B’ – U Value 1.4 W/m2K (using sealed unit 0.9 W/m2K)
Will these windows comply with UK Building Regulations?
Yes. Alitherm Heritage windows are designed to meet current UK building regulations for thermal performance and safety when installed to the correct specification.stars
Can I see Alitherm Heritage windows before ordering?
Yes. Visit our showroom in Keighley, West Yorkshire, where you can compare Heritage window systems, frame profiles, glazing bars and finishes. Call 01535 603909 to arrange an appointment.
Can you supply and install Heritage windows for my project?
Yes. We offer professional surveying and installation across Yorkshire and surrounding regions, including Greater Manchester, Lancashire and Cheshire. We also manufacture and deliver made-to-measure Heritage windows nationwide for supply-only projects.
Come and explore…
Aluminium Bi-fold Doors, Sliding Doors, Contemporary Glazing, Aluminium Heritage Windows and Traditional Steel Replacement Doors
