Slimline Steel-Look Aluminium Windows: The Crittall Look, Without the Cold
Thin black frames, small panes, that unmistakable 1930s and industrial look. Steel-framed windows are back, on Art Deco semis and inter-war villas, converted mills and warehouses, and brand-new extensions where an architect wants a crisp, graphic frame.
See also: Crittall-style doors → · Aluminium casement windows →
The catch with original steel windows is that they’re single glazed, they rust, and they’re freezing. Our slimline aluminium systems give you the look, ultra-slim profiles, slender glazing bars, black or any colour, with double or triple glazing, thermal breaks and modern locking. Supplied and fitted by our own team across Glasgow, Stirling and Scotland.
Where the steel look works
Replacing original steel windows
On 1930s houses and Art Deco villas across Glasgow’s suburbs.
Loft, mill and warehouse conversions
Merchant City, Finnieston, Stirling’s riverside.
Contemporary extensions
A glazed gable or a wall of small-pane glazing as the feature.
Internal screens and doors
A steel-look glazed partition between kitchen and living room, or a glazed room divider.
Front doors and side screens
A slim-framed glazed entrance. See our Crittall-style doors.
Conservation areas
Where the council wants the original steel proportions kept.
Two slimline ranges
Sheerline Classic slimline. Sheerline’s ultra-slim Classic window system was designed with steel replacement in mind: minimal profiles, fine sightlines and Thermlock® insulation. It takes slim applied or internal glazing bars to recreate the small-pane grid, and it matches Sheerline doors, bifolds and the S1 roof lantern.
Cortizo steel-look range. Cortizo’s Art Deco-inspired slimline profiles, with the same COR 70 performance underneath. Available as windows, doors and fixed screens, and matching Cortizo bifolds and Cor Vision sliders.
Both come in any RAL colour. Matt black and anthracite are the classics, with dual colour inside and out.
Getting the details right
The difference between a steel-look window that convinces and one that doesn’t is in the details:
- Glazing bars: slim bars in the correct proportion to the frame, laid out to match the original grid, applied to both faces of the glass with a spacer bar in the cavity so they read as true divisions.
- Frame proportions: slim outer frames and sashes, with matching sightlines on fixed and opening panes.
- Heritage detailing: sash horns and period details on request.
- Matt finishes: a matt or fine-textured black reads as steel; gloss doesn’t.
- Slender handles: heritage-style monkey-tail or slim lever handles in black or brushed finishes.
- Any shape or size: arched heads, circular porthole windows, tall narrow lights and full glazed gables.
Cill options
The cill is the shelf the window sits on outside, and it changes the look of the whole elevation more than most people expect. We offer three.
Stub cill
The slimmest option. Used where the original stone or concrete cill is staying and the window simply sits on top of it, or where you want the frame to look as minimal as possible.
Standard cill
The everyday choice for most Scottish homes. Enough projection to throw rain clear of the wall, with a clean, proportionate look.
Large cill
A deep cill for a stronger, more traditional line. Suits older properties, deep reveals and anywhere the window needs to stand out from the wall.
Drawn to scale: the dashed outlines show the other two sizes. On bays and runs of windows we weld the cill for one continuous line with no joins. The team will show you all three in the showroom.
Glazing options
- Double glazing as standard: A-rated, argon filled, low-E glass.
- Triple glazing: slimline aluminium frames carry it comfortably.
- Acoustic glazing: for city-centre conversions on busy streets.
- Integrated blinds: sealed inside the double-glazed unit (double glazing only).
- Obscure and reeded glass: reeded is a popular period choice for bathrooms and internal screens.
- Safety glass: toughened or laminated where required.
- Trickle vents: optional, recommended.
Steel-look aluminium vs real steel
Genuine steel windows are still made, and they’re beautiful, but they’re expensive, heavy, need repainting, and even the best modern steel systems can’t match aluminium for thermal performance.
Steel-look aluminium gives you the proportions at a fraction of the cost, with no maintenance and warmer rooms. For most homes it’s the better choice. If you have a listed building that insists on steel, we’ll tell you.
What do steel-look windows cost in Scotland?
Every steel-look project is bespoke. The profile, the number of panes, the glazing bar layout, the colour and the glass all change from house to house, so we don’t publish a starting price. Slimline aluminium costs more than standard aluminium and considerably less than genuine steel.
We give you one fair, fixed price after a free home survey. No countdown discounts, no pressure.
One system, one look
We don’t mix systems on a project. Sheerline windows, doors, bifolds, patio doors and the S1 roof lantern share one profile family and one colour run; Cortizo windows, bifolds and sliders share another. Choose one brand for the whole extension and every frame matches edge to edge. Handles and hardware match too, from the ERA and Fab&Fix ranges we fit across every product. Matching windows and doors →
No appointment needed
Our Glasgow showroom has a Crittall-style steel-look door on display, so you can see the slim black profiles and glazing bars up close. Stirling doesn’t have a steel-look display, but the team can show you the Sheerline and Cortizo ranges and talk you through the slimline options.
Glasgow Showroom
34 Houston Street, Kinning Park, Glasgow G5 8RS
0141 378 6400 · info@nu-view.co.uk
Mon, Tue, Thu 9am to 4:30pm · Fri 9am to 3:30pm · Closed Wednesday and weekends
Glasgow showroom →Stirling Showroom
Block 4, Unit 6, 20 Munro Road, Springkerse, Stirling FK7 7UU
01786 437 209 · info@nu-view.co.uk
Mon to Thu 9am to 4:30pm · Fri 9am to 3:30pm · Closed weekends
Stirling showroom →Your questions answered
Is this the same as Crittall?
Crittall is a brand of steel window. Our slimline aluminium systems recreate the Crittall look, slim black frames and small panes, in thermally broken aluminium with double or triple glazing.
Can you match my existing 1930s steel windows?
Usually very closely. Bring photos and measurements to the Glasgow showroom, where you can see our steel-look door, and we’ll lay out the glazing bars to match the original grid.
Can I have the steel look on an internal screen or door?
Yes. Steel-look internal screens and glazed doors are one of the most popular uses: a kitchen-to-living-room divider, or a glazed wall to a home office.
Will a conservation area accept aluminium instead of steel?
Often, provided the proportions and colour match. We’ll advise on your street before you apply.
Can I match the windows to a steel-look front door or bifolds?
Yes. The same profiles and colours run across windows, doors, screens and bifolds.
Why do windows get condensation, and will new windows stop it?
Condensation forms when warm, moist air meets a cold surface, and old glazing is usually the coldest surface in the room. New A-rated windows are much warmer on the inside, so condensation drops dramatically, but because they are far more airtight it can still appear, especially in the first winter. The fix is ventilation: extractor fans, open trickle vents and airing rooms briefly each day. Condensation on the outside of new glass on cold mornings is a good sign, as it means the low-E coating is keeping heat inside. Condensation between the panes means the sealed unit has failed and is covered under guarantee.
Do you fit steel-look windows outside Glasgow and Stirling?
Yes, across Scotland including Falkirk, Lanarkshire, Dunbartonshire, Renfrewshire and Perthshire.
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