The Forge
Luxury homes · Contemporary extensions · Commercial buildings · Architectural renovation · Security-conscious projects
Key details
- Thermally broken steel · U-values down to 1.1 W/m²K
- 25mm visible profile width · 80mm system depth
- Compatible with double and triple IGUs up to 27mm
- Glass options include fluted, frosted, textured and tinted
- Multi-point locking system
- Applied and structural glazing bar options
- Maximum sash 1000mm × 2800mm
- Nearly 100% recycled steel content
- Any RAL colour · bespoke finish
Available as
Windows · Single doors · Double doors · Side screens · Top screens · Fixed walls (Bifold in development)
The case for thermally broken steel, made without argument
The case for thermally broken steel is straightforward: the material has no equal for strength and character, and a proper thermal break means it no longer has to apologise for energy performance either.
The Forge makes that case without needing to argue it. A 25mm visible profile width and 80mm system depth give it the structural integrity to handle large openings and high wind loads, while U-values down to 1.1 W/m²K put it alongside the better-performing aluminium systems on the market — without any of the visual compromise. Multi-point locking, angled glazing and compatibility with double and triple insulated units up to 27mm complete a system that’s genuinely built for demanding external conditions.
Maximum sash dimensions of 1000mm × 2800mm cover most residential and light commercial applications. Bespoke glazing bars — applied and structural — are available for projects where the visual character of the frame matters as much as its performance.
Internal door collections
Three families.
Every door type.
Internal – original profile
Internal steel doors & partitions
Twenty millimetres of steel frame. Everything else is glass, light and space. The Foundry is our original slim internal profile — hand-welded, precisely crafted, and designed to let a room breathe.
Internal – ultra-slim
Internal steel doors & partitions
Ultra-slim sightlines from 13mm. A profile inspired by Art Deco precision and classic industrial glazing — made for interiors where the frame should almost disappear.
Internal – maximum light
Internal steel doors & screens
The look of premium fire-rated steel glazing — without the fire-rated price. The Lumière delivers the same refined heritage appearance as the Lumière Sentinel E30, at approximately 35% less. For projects where consistency matters as much as budget.
Internal – maximum light
Internal steel doors, partitions & shower enclosures
The character of 1920s steel glazing, faithfully recreated for interiors. Designed to match the Heritage W40 external system — for projects where authenticity matters as much as architecture.
Internal – maximum light
Internal steel doors & partitions · New
A premium slim steel profile designed to move seamlessly from outside to in. The internal counterpart to the Signature External — same sightlines, same character, complete architectural continuity.
Describe your space. We'll take it from there.
Get your quote — no pressure, just expert advice.
EXTERNAL DOORS & WINDOWS
The Threshold collection.
Outside, redefined.
External
Ottostumm · External steel windows & doors
Hot-rolled steel with the strength and character that cold-formed profiles can’t replicate. The Heritage is built for the projects where authentic industrial architecture isn’t an aesthetic choice — it’s the only acceptable answer.
External
Thermally enhanced steel entrance doors
The same refined proportions as the Signature Internal — engineered for the outside. Thermally enhanced, weather-tested and designed to perform as well as it looks at the entrance to a building.
External
Thermally broken external steel windows & doors
The look of premium fire-rated steel glazing — without the fire-rated price. The Lumière delivers the same refined heritage appearance as the Lumière Sentinel E30, at approximately 35% less. For projects where consistency matters as much as budget.
External
TB PRO · Thermally broken steel doors & windows · external
Thermally broken steel at a more accessible price point. The Forge Pro brings reliable insulation, smooth operation and the quiet integrity of steel to projects where performance matters but budget is part of the conversation.
External
Thermally broken external steel windows & doors
PAS 24 certified security. Acoustic performance to 45dB. U-values to 1.2 W/m²K. Ultra-slim sightlines. The Artesa is the system for projects where every performance metric matters — and so does how it looks.
Come in with a floor plan, a question, or just a feeling. We'll start from there.
1 Courtenay Road
East Lane Business Park
Wembley
LONDON
HA9 7ND
FIRE-RATED RESIDENTIAL
The Sentinel range
Protected without compromise
Fire-rated
E30 fire-rated steel doors · Internal & external
Certified fire protection without the compromise. The Sentinel delivers E30 to E120 fire resistance, acoustic performance up to 44dB and genuine steel durability — for residential and commercial projects where performance is the brief.
Fire-rated
E30 · Internal fire-rated steel doors & screens · New
E30 certified. Heritage proportions. Designed to be indistinguishable from its non-fire-rated twin. The Lumière Sentinel exists so that fire protection never has to look like fire protection.
Fire-rated
E30 · Internal fire-rated steel doors & screens
Slim, decorative and E30 certified. The Primo brings heritage glazing bar character to fire-rated steel — for interiors where protection is required but the door still has to earn its place in the room.
Fire-rated
EI30 · Internal fire-rated steel doors · New
EI30 certified — fire integrity and thermal insulation combined. The Resilience meets current UK Building Regulations for fire protection, without compromising the architectural quality of the door itself.
