Heritage Steel-Look Windows — London & the Home Counties
The look of an original 1930s Crittall or 1950s factory window, delivered in thermally-broken aluminium with A-rated glazing. Slim 20mm astragal bars, matte black powder coat and the same tight sightlines the originals became famous for — without the rust, the cold bridge or the maintenance.
20mm astragal in aluminium
The bar profile is a 20mm applied astragal jointed duplex-butt at every intersection — replicating the visual weight of an original Crittall W20 steel window, on a modern thermally-broken aluminium frame that eliminates the cold bridge.
Overview
A closer look at what makes the heritage steel-look windows range distinctive — the specification, the styles, the process, and the answers to the questions we get asked most.
Thermally-broken aluminium heritage profile · 20mm applied astragal bars with duplex-butt jointing · Qualicoat Class 2 matte polyester powder coat · argon-filled toughened A-rated glazing
Authentic 20mm Astragal Bars
Slim mechanical grid bars that replicate original steel window proportions — 20mm on horizontal and vertical intersections, applied through-frame with duplex-butt jointing.
Matte Black Powder Coat
The signature finish — RAL 9005 matte black powder coat, or any RAL to match architect specification. Qualicoat Class 2 guaranteed for 20 years.
Thermally-Broken Aluminium
34mm polyamide thermal break inside the aluminium profile — no cold bridge, no condensation, U-values from 0.9 W/m²K. The original steel windows had none of this.
Casement or Fixed
Available as side-hung casements, top-hung vents, fixed lights and French pair configurations — matched across a full elevation.
Art Deco & Modernist Suited
The right window for warehouse conversions, factory conversions, 1930s Art Deco villas and contemporary modernist new-builds — anywhere a heavy timber sash would feel wrong.
PAS 24 Secured Locking
Concealed multi-point locking on all opening sashes and toughened inner glazing — modern security in a period-look frame.
Three material ranges, one configuration.
The heritage steel-look configuration is available across every one of our window ranges — the material choice is yours.
Engineered to the millimetre.
Every frame we install is made to your survey sizes with the following performance envelope as standard.
- U-value (whole window)
- 0.9 – 1.4 W/m²K
- Bar profile
- 20mm applied astragal · through-frame duplex-butt jointing
- Finish
- RAL 9005 matte black standard · any RAL to order
- Configurations
- Side-hung · top-hung · fixed · French pair
- Security
- PAS 24:2016 · concealed multi-point locking
- Systems
- Smart Heritage · AluK 58BW Heritage · similar
Heritage Steel-Look Windows across London
and the Home Counties.
We install heritage steel-look windows across six counties — every project surveyed, made and fitted by our in-house team. Choose your county to read local knowledge, planning notes and recent work.
See all areas coveredHeritage Steel-Look Windows — installed.
A selection of recent installations across London and the Home Counties, photographed on site.
Practical answers.
Everything homeowners ask us about heritage steel-look windows — survey, lead times, guarantees and coverage.
Is this the same as a real Crittall window?+
It's an aluminium replica of a Crittall — the appearance is very close but the frame is thermally-broken aluminium rather than steel. Original Crittall (rebranded W20 or Corporate W20) is still available in real steel, with worse thermal performance and additional maintenance requirements.
Are they suitable for a listed building?+
Sometimes — where the original windows were steel and the officer accepts an aluminium replacement. Some listed properties will require true steel; we can quote both options at survey.
How is thermal performance vs the original?+
Substantially better. Original steel windows had U-values around 5.0 W/m²K and cold bridged badly. Our aluminium heritage profile achieves 0.9–1.4 W/m²K and eliminates the internal cold bridge entirely.
What sizes are practical?+
Standard casement sashes up to 800mm × 1200mm, fixed lights up to 1400mm wide. Larger apertures are divided into ganged frames with structural mullions — the same way the originals were.
Enquire about
Heritage Steel-Look Windows.
Speak with our design team, book a home survey, and receive a fixed written quotation — all with no obligation.
Call · 020 3633 0405