What are Crittall doors?

Crittall doors are steel-framed glazed doors and screens with slim black sightlines and a grid of glazing bars, a style that began in industrial and 1920s to 1930s buildings. Crittall is a registered trade mark of Crittall Windows Ltd, whose sections are hot-rolled steel to BS 6510, so anything they did not make is Crittall-style, and most of it is steel-look aluminium.

How much do Crittall-style doors cost?

Indicative supply costs are £1,800 to £3,200 per linear metre of opening for hot-rolled steel and £900 to £1,600 for steel-look aluminium, before fitting. Fitting adds £300 to £800 per opening, at two fitters on £150 to £200 each per day. Thermally broken external sets start around £1,200 per linear metre in aluminium. Steel is made to measure with no published list price, so treat these as a starting point.

Are Crittall doors good for internal use?

Yes. Internally no thermal standard applies, so single glazing is fine, and a screen keeps light and the sightline through an open-plan kitchen-diner while containing cooking smells. It will not block much sound. Glass in a door or within 300mm of one, below 1,500mm, must be toughened or laminated, and a screen onto a protected stair in a house with a floor over 4.5m up needs 30 minute fire-rated glazing.

Are steel or aluminium Crittall-style doors better?

Genuine steel offers the most authentic slim sightlines and heritage feel but costs more and, externally, needs good thermal detailing. Modern aluminium Crittall-style systems achieve a similar look with better thermal performance and lower cost, which is why many external installations use aluminium. The right choice depends on budget and whether the doors are internal or external.

Do Crittall doors suit period homes?

Inside, yes, particularly in 1920s and 1930s and Art Deco houses where the style is original. On the outside of a period house, position decides it: a rear elevation is usually straightforward, but a front elevation in a conservation area rarely gets permission, an Article 4 direction can make even a like-for-like change need an application, and on a listed building any alteration needs listed building consent.

Crittall-Style Doors: Cost, Ideas & Are They Worth It?

Q: Do Crittall-style doors need building regulations approval?

Internal screens face no thermal standard, but Approved Document K treats glass below 1,500mm in a door, or in a side panel within 300mm of one, as a critical location, so it must be toughened or laminated. Externally, a door with more than 60% of its internal face glazed must achieve 1.4 W/m²K or a Doorset Energy Rating of band C under Approved Document L, which single glazing cannot do. And where a floor sits more than 4.5m above ground, a screen onto the staircase needs 30 minute fire-rated glazing.

Key Takeaways

Crittall is a registered trademark owned by Crittall Windows Ltd. Anything they did not make is Crittall-style.
Indicative supply cost is £1,800 to £3,200 per linear metre for hot-rolled steel against £900 to £1,600 for steel-look aluminium.
Internally there is no thermal standard, so single glazing is fine.
Externally a glazed door must hit 1.4 W/m²K or Doorset Energy Rating band C under Approved Document L.
Glass below 1,500mm in a door must be toughened or laminated, and a screen onto a protected stair needs fire-rated glazing.

A black steel framed glazed screen dividing one room from the next.

Slim black steel frames and gridded glass are one of the most recognisable looks in London renovations. Here is what they cost, what the regulations ask of them, and when aluminium is the better answer than steel.

What are Crittall-style doors?

Crittall doors are steel-framed glazed doors and screens with slim black sightlines and a grid of glazing bars, an industrial and 1920s-30s heritage style. The name is a registered trade mark, not a category: Crittall Windows Ltd owns and enforces it, so anything they did not make is Crittall-style. Genuine sections are hot-rolled steel to BS 6510 (the W20 range), welded, galvanised and powder coated. Steel is roughly three times stiffer than aluminium, which is the point: the same pane needs less frame around it.

Source: Crittall Windows Ltd trade mark and product information, 2026.

Internal screens: the big trend

The most popular use by far is as an internal screen in an open-plan kitchen-diner, and it is an easy job because no thermal standard applies to an internal partition. A fixed screen gives the most glass per pound, a hinged door within a screen is the classic kitchen-to-hallway arrangement, and a pocket slider is the neatest and the dearest. It contains cooking smells and keeps a sightline through the plan, the signature move of broken-plan living, but it will not block sound.

Two rules catch people out. Glass in a door, or a side panel within 300mm of one, is a critical location under Approved Document K up to 1,500mm above floor level and must be toughened or laminated. And where a floor sits more than 4.5m above ground, which covers most three-storey London terraces and any loft conversion, the stair is a protected escape route, so a screen onto it needs 30 minute fire-rated glazing in a certified frame.

Source: gov.uk Approved Document K, impact with glazing, and Approved Document B Volume 1, protected stairways, 2026.

What do Crittall-style doors cost?

Steel-look aluminium costs roughly half what hot-rolled steel does. Figures are per linear metre of opening width, supply only.

Option	Indicative supply, per linear metre	Notes
Steel-look aluminium internal screen	£900 to £1,600	Single glazed, 4 to 8 week lead times
Hot-rolled steel internal screen	£1,800 to £3,200	Made to measure, 8 to 14 weeks
Thermally broken aluminium external set	£1,200 to £2,200	Double glazed, meets Approved Document L
Hot-rolled steel external set	£2,500 to £4,500	Must be a thermally broken system
Fire-rated internal screen, 30 minutes	£2,500 to £4,000	Certified glass and frame, tested as an assembly

Aluminium rates anchored to PriceYourJob, 2025 (frames around £1,000 per metre of width, fitted sets £1,800 to £3,500). Steel and fire-rated figures are indicative: the steel makers publish no list prices. Fitting is extra, at two fitters on £150 to £200 each per day, so allow £300 to £800 per opening.

What do the regulations ask externally?

A new or replacement external door with more than 60% of its internal face glazed must achieve 1.4 W/m²K or better, or a Doorset Energy Rating of band C, under Approved Document L. Single-glazed steel is nowhere near that, so it is an internal product unless the maker supplies a thermally broken, double-glazed version and the figures to prove it. That is why most external steel-look installations in London are thermally broken aluminium in a matt black powder coat: bare steel runs cold and attracts winter condensation, and the systems that fix it thicken the sections, eroding the advantage you bought steel for. Our building regulations guide covers the sign-off.

Source: gov.uk, Approved Document L Volume 1, Dwellings, 2021 edition incorporating 2023 amendments, Table 4.2. The 2026 edition, effective 24 March 2027, keeps the same 1.4 W/m²K door standard.

Are Crittall-style doors worth it?

Internally, usually yes; externally, only if you buy the right product for the job. An internal screen does something no plain door or open archway does: it keeps light and the sightline through the plan while holding cooking smells and some of the noise in the kitchen. On the figures above, a 2.4 m steel-look aluminium screen is roughly £2,200 to £3,800 supplied before fitting, and hot-rolled steel about double that, so aluminium is the value choice for most internal jobs and steel is for the client who wants the thinnest possible sections.

Worth it: an internal screen between kitchen and dining or hall, a glazed door onto a dark hallway, or a rear elevation where the grid suits the house.
Think twice: single-glazed steel on an outside wall, which fails Approved Document L and runs with condensation in winter; and a gridded front door in a conservation area, which rarely gets permission.
Lifetime cost: powder-coated aluminium needs little more than cleaning, while steel needs any chip in the coating touched up promptly before it rusts.

Nobody publishes reliable resale data for glazed screens, so treat one as a quality-of-life purchase rather than an investment.

Where they work in London

Internally there are no planning constraints, unless the building is listed, when even an internal screen can need listed building consent. Externally, position matters more than style. On a rear elevation, including a side return, steel-look glazing is usually straightforward. On a front elevation in a conservation area it rarely is, and where an Article 4 direction applies, as across large parts of Islington, Camden, Hackney and Kensington, even a like-for-like change needs permission. On a listed building, any alteration needs listed building consent. Read the conservation area guide and the listed building guide before you order, and check the permitted development rules for the rear.

One practical warning: screens are made to plus or minus 1.5mm, so form the opening, install any structural beam and fix the finished floor level before the survey, or an 8 to 14 week steel order will arrive and not fit. Compare external glazing in our bi-fold vs sliding doors guide, and see maximising natural light. GS Renovation fits screens as part of open-plan conversions across London, so contact us or call 07472 424 226.

Abdelaaziz Saaid

Abdelaaziz Saaid is the founder and director of GS Renovation Ltd. With over 30 years delivering structural, renovation and extension projects across London, these guides reflect his hands-on site experience and current UK building practice.

Crittall-Style Doors