Sheerline Classic Heritage Doors
Slimline, Stepped-Profile Steel-Look Doors for Period & Contemporary Homes
Traditional Steel-Look Doors
Sheerline Classic Heritage Doors
Sheerline Classic Heritage doors are stepped-profile, steel-look aluminium doors that capture the elegance of traditional steel in an aluminium system, with ultra-slim frames, strong thermal performance and a distinctive stepped exterior profile inspired by early 20th-century steel framing.
They’re ideal for period homes, listed and conservation-led renovations, retro refurbishment projects and contemporary extensions, and they pair with the Sheerline Classic Heritage window range for a fully coordinated finish.
Explore Our Heritage Door Systems
Which Heritage Door Is Right for You?
Sheerline Classic is the stepped-profile option within our heritage door range. Our flat-profile ranges, Alitherm Heritage and Alitherm Heritage 60 , offer a smoother steel-look sightline, while the AluSpace internal system brings the same styling indoors.
See the Full Heritage Door Range →Compare all four heritage door systems.
What Is Sheerline Classic?
The Sheerline Classic door takes its name from Sheerline’s own Classic Heritage system, and it’s easy to see why – the signature stepped exterior profile and transom are what give it away as a genuine steel-look door rather than a standard aluminium one, and what set it apart from the flatter, square-edged framework of our other heritage systems. Sightlines as slim as 35.5mm, PAS24 security accreditation and Thermlock® multi-chamber thermal technology mean it doesn’t just look the part, it performs like a modern door too.
Key Features
35.5mm ultra-slim sightlines, stepped exterior profile
U-value of 1.4 W/m²K, double glazed, Part L compliant
Thermlock® multi-chamber technology for enhanced insulation
PAS24 Secured by Design accredited, with optional SBD approval
10-year manufacturer warranty, 25-year paint finish guarantee
Wider sash sizes up to 1m
12 standard powder-coated finishes, plus the full range of RAL colours
Sheerline Classic Doors: Colours & Configurations
Every Sheerline Classic door is made to order around your opening and style preferences, with single doors, French doors, side panels, top lights, and both horizontal and vertical glazing bar layouts available. Choose from 12 standard powder-coated colours, from Jet Black and Anthracite Grey through to Pastel Turquoise, or ask about a bespoke RAL finish.
Classic Heritage Single Door No Bars Anthracite
Classic Heritage Single Door 2 Bars Pure White
Classic Heritage Single Door 4 Bars-Jet Black
Classic Heritage Single Door Top Light No Bars Squirrel Grey
Classic Heritage Single Door Top Light 2 Bars Pastel Turquoise
Classic Heritage Single Door Top Light 4 Bars Black-Metallic
Classic Heritage French Door No Bars Agate Grey
Classic Heritage French Door 2 Bars Cream
Classic Heritage French Door 4 Bars Silver Metallic
Suitable for Listed Buildings, Conservation Areas & Period Homes
Sheerline Classic’s slim profile and traditional styling have been approved for listed building and conservation area projects by a number of local authorities, including the London Boroughs of Islington, Camden and Tower Hamlets, Watford Borough Council, Essex County Council, Leeds City Council, and Cadw. Final approval depends on your specific property and local authority.
We also offer a free sample service to help with surveying decisions, design choices or planning applications – just call us on 01535 603909 and ask.
Transform Your Space
Whether you’re looking for the perfect looking door to bring more light into a kitchen/diner extension or need to find a sympathetic replacement door for a period refurbishment project, the Classic Heritage Door offers the style you are after.
“Marlin went above and beyond to ensure our measurements and doors were exactly how we wanted them. The quality of the doors are amazing and they look beautiful in our space. We would highly recommend using this company. We have visited a lot of companies and you can’t beat this process and quality. If you are unsure visit their showroom it’s well worth having a chat with Adrian and the team”.
Anesa Harambasic
Why Homeowners Choose Marlin
As a family-run manufacturer of heritage aluminium systems in Keighley, West Yorkshire, we combine over 20 years of expertise with quality materials and a 10-year warranty for complete peace of mind.
“Excellent customer service from enquiry to delivery. Thank you to Hannah, Adrian and the team for going the ‘extra mile’.” — Caroline Dyson, Bingley
“I’d wholeheartedly recommend Marlin Windows. We ordered Steel Replacement French Patio doors and Windows. They are absolutely beautiful, and they were an absolute pleasure to deal with. Thanks Marlin!” — Myar Craig-Brown, London
Visit Our Keighley Showroom
For inspiration, help and advice, visit our showroom in Keighley, West Yorkshire. 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.
Just call 01535 603909 to book.
Supply & Installation Options
Choose professional installation across our regional service area or nationwide supply-only delivery.
Supply & Install
Professional survey and installation across West & South Yorkshire, Greater Manchester, Merseyside, Lancashire, Derbyshire, Nottinghamshire, East Riding and Cheshire.
Supply Only – Nationwide
Made to measure in Yorkshire and delivered nationwide, ready for your builder or installer.
Outside our installation area? We can still supply and deliver nationwide.
“I’d wholeheartedly recommend Marlin Windows. We ordered Steel Replacement French Patio doors and Windows. They are absolutely beautiful. And they were an absolute pleasure to deal with. Thanks Marlin!”
Myar Craig-Brown
London
Colour Options
12 standard colours in our hard wearing powder coated finish.
Helpful guides
IS ALUMINIUM A SUITABLE ALTERNATIVE FOR THE REPLACEMENT OF STEEL PRODUCTS?
Steel look Aluminium Windows, Doors and Internal Room Dividers and Doors look very similar to their Steel counterparts but offer several benefits of being Aluminium.
The benefits of modern, secure, thermally efficient aluminium windows with the heritage and character of traditional steel at a fraction of the cost.
Frequently Asked Questions
How energy-efficient are they?
A U-value of 1.4 W/m²K with double glazing, thanks to Thermlock® multi-chamber technology, and full compliance with Part L of the UK building regulations.
Are they suitable for listed buildings or conservation areas?
Yes, subject to approval by your specific local authority.
How long do Sheerline Classic doors take to make?
We can typically have your doors ready within around 4 weeks for supply only, though lead times vary by season and project size – please contact our team for a current estimate.
How secure are they?
PAS24 Secured by Design accredited, with high-security multi-point locking, unique hinge protectors and optional SBD approval.
What information do you need for a quotation?
Approximate dimensions (width x height), a basic design or layout, and your project location.
What colours are available?
12 standard powder-coated colours as standard, from classic black and white through to bronze, turquoise and metallic finishes, or ask about a bespoke RAL colour match.
Ready to transform your home?
Get a made-to-measure quote for your Classic Heritage doors 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.
Come and explore…
Aluminium Bi-fold Doors, Sliding Doors, Contemporary Glazing, Aluminium Heritage Windows and Traditional Steel Replacement Doors