At Direct Trade Windows, our steel-look Alitherm Heritage doors from Smart deliver the perfect balance of classic styling and modern performance. Designed to replicate the timeless appeal of traditional steel doors, these aluminium systems feature elegant lines, heritage-style glazing bars, and a refined finish�ideal for period renovations, internal partitions, or contemporary spaces looking for industrial charm.
Engineered with polyamide thermal break technology, Alitherm Heritage doors provide excellent energy efficiency and comply with Document L regulations. Whether used as interior room dividers or secure external doors, they offer robust weather performance, PAS24-certified security, and enduring style�making them a smart and compliant choice for both heritage and modern builds.
Visit our showroom to explore our full range of steel-look aluminium doors and speak with our expert team about finding the right solution for your project.
We offer two steel-look Alitherm Heritage door options to suit different design goals and budgets. Our premium variant features ultra-slim 25mm glazing bars for a more refined, authentic steel aesthetic. Alternatively, the 48mm option offers the same great performance and styling with slightly bolder bars�ideal for a cost-effective, durable solution. Both options are manufactured in-house for quality assurance and are available in a wide range of colours, finishes, and configurations.
Profile width: 25 mm ultra-slim sash
Profile width: 48 mm standard sash
When a project specifies steel-look doors with arched window heads, we manufacture both from the same source. See our dedicated range of arched and curved aluminium windows — in-house bending to a minimum 350 mm radius, ±1 mm tolerance, fabricated on the same Fom Industrie equipment as the steel-look door range. Cortizo Cor 70 and Smart Alitherm Heritage profiles available.
Technical Specification
Brand: Alitherm
Material: Aluminium polyamide
Thermal break: Yes
Dual colour option: Available
NBS specification: Available
WER rating: B
U-Value: 1.6W/m�K (using 1.0W/m�K glass unit)
Document L compliant: Yes
Kitemark certified: Yes
BS 6375-1:2009 Compliant: Yes
BS 4873 Compliant: Yes
Single door max width: 900mm
Single door max height: 2100mm
Glazing options: 24mm, 28mm, 32mm & 36mm double or triple glazed units
Frame depth: 47mm
Typical sightlines: 59mm
Glazing method: Tape or gasket glazed
Locking system: Multi-point locking and face mounted shoot bolts
Hardware options: 316 Marine Grade Stainless Steel, Heritage and Art Deco styles
Weather performance (open in): Air Permeability Class 4 (600Pa), Watertightness Class 3A (100Pa), Wind Resistance Class 3 (1200Pa)
Weather performance (open out): Air Permeability Class 4 (600Pa), Watertightness Class 8A (450Pa), Wind Resistance Class 3 (1200Pa)
Security standard: Tested to PAS24:2016
Finish options: Standard or non-standard colours, metallic, Smart's Sensations textured, and Alchemy anodised effect finishes
Colours
Modern steel look bifold doors enhancing home aesthetics and functionality.
Bifold doors with a sleek steel finish for modern home design. Perfect for creating seamless indoor-.
Bifold doors with a sleek steel finish for modern home design.
Modern steel look bifold doors enhancing contemporary home aesthetics.
Bifold doors with a sleek steel finish for modern home design. Perfect for creating seamless indoor-.
Bifold doors with a sleek steel finish for modern home design. Perfect for creating seamless indoor-.
Stylish steel-look bifold doors for modern home design.
Bifold doors with a sleek steel finish for modern home design.
Bifold doors with a sleek steel finish for modern home design.
Bifold doors with a sleek steel finish for modern home design.
Modern steel look bifold doors opening to a bright outdoor space.
Bifold doors with a sleek steel finish, ideal for contemporary interiors and outdoor transitions.
Bifold doors with a steel finish, offering sleek design and durability for contemporary interiors.
Aluminium bifold doors with a steel finish, offering sleek aesthetics and seamless indoor-outdoor tr.
Modern steel look bifold doors opening to outdoor space, enhancing natural light and style.
Modern steel look bifold doors opening to outdoor space, enhancing natural light and style.
Glass Options
A sleek, modern steel-look window with a minimalist frame design.
Steel look window with black frame for contemporary doors and bifolds.
Steel look window with black frame for contemporary doors and bifolds.
Modern steel-look window with sleek black frame and clear glass.
Steel look window with sleek black frame for modern doors and bifolds.
Modern steel-look window with black frame for stylish doors and bifolds.
Modern steel look window with black frame and clear glass panel.
Steel Look Window with Black Frame for contemporary doors and bifolds.
Brochure
Gallery
Steel-look doors from Direct Trade Windows provide a blend of minimalist style, premium aesthetics, and high performance. They offer outstanding thermal efficiency and boast some of the lowest U-values available on the market.
Our steel-look doors, crafted by Smart, offer a clean and minimalist style that presents beautiful slim lines, ensuring stunning aesthetics for your space.
The steel-look doors come in a variety of elegant designs, providing you with over 20 options to choose from, allowing you to find the perfect fit for your space.
Absolutely, our steel-look doors offer versatility through a range of colours and polyester powder coatings. Additionally, they come with several laminate glass options, allowing for a tailored appearance.
Yes, our steel-look doors meet high security standards, as they are accredited to PAS24 standards, ensuring your peace of mind.