Crittall Style Doors: A Comprehensive UK Homeowner's Guide

In the world of architectural design, certain styles transcend fleeting trends to become timeless classics. Crittall style doors and windows are a prime example, their distinctive aesthetic having graced properties across the UK for over a century. Originally manufactured by the British company Crittall Windows Ltd, this iconic design is now widely replicated, offering homeowners a blend of industrial chic, elegant minimalism, and impressive functionality. But what exactly are Crittall style doors, and what should UK homeowners consider before investing in them?

What Are Crittall Style Doors?

Crittall style doors are characterised by their slim, steel-framed profiles and multiple glazing bars, creating a grid-like appearance. This design originated in the late 19th and early 20th centuries, becoming a hallmark of Art Deco, Modernist, and Industrial architecture. While the original Crittall company still produces these high-quality steel frames, the term 'Crittall style' now broadly refers to any door or window that emulates this distinctive aesthetic, often using alternative materials like aluminium or even uPVC to achieve a similar look.

Key Characteristics:

• Slim Profiles: The inherent strength of steel (or modern aluminium alternatives) allows for exceptionally slender frames, maximising glass area and light transmission.
• Grid-Like Glazing: Multiple panes of glass are separated by narrow glazing bars, creating a distinctive segmented appearance.
• Materiality: Traditionally made from hot-rolled steel, modern interpretations often use thermally broken aluminium for improved thermal performance.
• Colour: Typically finished in black or dark grey, though other powder-coated colours are available.
• Versatility: Available as internal partitions, external doors (including French, bi-fold, and sliding options), and fixed screens.

Benefits for UK Homes

Choosing Crittall style doors offers a multitude of advantages that go beyond their striking appearance.

Materials and Construction: Steel vs. Aluminium

While the original Crittall doors are made from steel, the market now offers high-quality alternatives, predominantly in aluminium. Understanding the differences is crucial for making an informed decision.

Steel Crittall Doors (Authentic)

• Material: Hot-rolled steel.
• Profiles: Exceptionally slender, often the slimmest available, due to steel's inherent strength.
• Thermal Performance: Traditional steel frames are highly conductive, meaning they can transfer heat easily. Modern steel frames from reputable manufacturers often incorporate thermal breaks to improve insulation, but this can increase profile thickness slightly.
• Weight: Heavier than aluminium, which can impact installation and require robust supporting structures.
• Cost: Typically the most expensive option due to material and manufacturing processes.
• Maintenance: Requires professional finishing (e.g., galvanising and powder coating) to prevent rust.

Aluminium Crittall Style Doors (Modern Alternative)

• Material: Aluminium, often recycled.
• Profiles: Very slim, closely mimicking the steel aesthetic, though often slightly thicker than the slimmest steel profiles.
• Thermal Performance: Almost always feature thermal breaks as standard, offering excellent insulation and making them highly compliant with modern Building Regulations for external applications.
• Weight: Lighter than steel, making installation potentially easier and reducing structural demands.
• Cost: Generally more affordable than authentic steel, offering a cost-effective way to achieve the look.
• Maintenance: Highly resistant to corrosion; requires minimal maintenance beyond cleaning.

UK Building Regulations and Technical Considerations

When installing new or replacement doors, especially external ones, compliance with UK Building Regulations is paramount. This ensures your home is safe, energy-efficient, and structurally sound.

Part L (Conservation of Fuel and Power)

Part L of the Building Regulations sets standards for the thermal performance of dwellings. For doors, this is measured by the U-value (W/m²K), which indicates how well a component insulates. A lower U-value means better insulation.

• New Build & Extensions: External doors must achieve a U-value of 1.2 W/m²K or lower.
• Replacement Doors: External doors must achieve a U-value of 1.4 W/m²K or lower.

Achieving these U-values with Crittall style doors typically requires:

• Thermally Broken Frames: As discussed, this is crucial for both steel and aluminium.
• Double or Triple Glazing: Standard double glazing with a low-emissivity (low-e) coating and argon gas fill is usually sufficient for 1.4 W/m²K. For 1.2 W/m²K, high-performance double glazing or even triple glazing might be necessary, particularly with larger glass areas.
• Warm Edge Spacers: These separate the glass panes and reduce heat transfer at the edges.

Part B (Fire Safety)

For internal Crittall style doors, particularly those separating habitable rooms from stairwells or integral garages, fire resistance might be required. Fire-rated Crittall style doors are available, incorporating specialist fire-resistant glass and intumescent strips within the frame. Always check with your local Building Control for specific requirements.

Part K (Protection from Falling, Collision and Impact)

Glazing in doors must be safety glass (toughened or laminated) in critical locations to prevent injury from impact. This is standard for most modern doors but worth confirming.

Planning Permission and Listed Buildings

While internal alterations rarely require planning permission, external changes to your home might, especially if you live in a Conservation Area or a Listed Building. For Listed Buildings, replacing original Crittall windows or doors with modern alternatives (even authentic ones) often requires Listed Building Consent. It's advisable to consult with your local planning authority before undertaking any work.

Specification Comparison: Steel vs. Aluminium Crittall Style Doors

This table summarises the key differences to help you decide:

Feature	Authentic Steel Crittall	Aluminium Crittall Style
Profile Slenderness	Extremely slim (can be 20-30mm)	Very slim (typically 30-50mm)
Thermal Performance (External)	Requires thermal breaks; can be challenging to meet 1.2 W/m²K without careful specification.	Thermally broken as standard; easier to meet 1.2-1.4 W/m²K with high-performance glazing.
Durability	Excellent, very strong.	Excellent, strong and corrosion-resistant.
Weight	Heavy	Lighter
Maintenance	Requires professional finishing to prevent rust; re-painting may be needed over time.	Low maintenance; powder coating is very durable.
Cost	Higher	Moderate
Aesthetic	Authentic industrial heritage look.	Modern interpretation, very similar aesthetic.
Typical Glazing	Double glazing (often with low-e and argon).	Double glazing (often with low-e and argon), triple glazing possible.

Installation and Maintenance

Regardless of the material chosen, professional installation is crucial for Crittall style doors. The precision required for fitting slim frames and multiple glass panes, coupled with ensuring weather-tightness and smooth operation, demands experienced installers. For external doors, proper sealing and drainage are vital to prevent water ingress.

Maintenance:

• Cleaning: Regular cleaning of glass and frames with mild soap and water is usually sufficient. Avoid abrasive cleaners.
• Hardware: Periodically check hinges, handles, and locks for smooth operation. Lubricate moving parts as recommended by the manufacturer.
• Finishes: For steel, monitor the paint or powder coat for any signs of damage that could lead to rust. Aluminium powder coatings are very durable but can be touched up if scratched.
• Seals: Inspect rubber seals around the glass and frame for perishing or damage, which can affect thermal performance and weather-tightness.

Choosing the Right Supplier

When considering Crittall style doors for your UK home, selecting a reputable supplier and installer is paramount. Look for companies with a proven track record, who can demonstrate expertise in both the products and their installation. They should be able to:

• Provide detailed technical specifications, including U-values.
• Offer a range of material options (steel and/or aluminium).
• Advise on compliance with UK Building Regulations relevant to your specific project.
• Offer comprehensive warranties on both the product and installation.
• Provide examples of previous work and potentially customer references (though you should verify these independently).

At Shard AG, we specialise in high-quality architectural glazing solutions, including a stunning range of Crittall style doors and windows. Our expert team can guide you through the options, ensuring your chosen doors not only enhance your home's aesthetic but also meet all relevant UK Building Regulations for performance and safety. We pride ourselves on precision manufacturing and professional installation, delivering bespoke solutions tailored to your unique requirements.