Last updated: 3 August 2026
Fabco is a British bespoke manufacturer that stands apart. The company offers a PAS 24 compliant security specification and genuinely minimalist steel glazing (with sightlines of just 10mm), without forcing homeowners to choose between the two. That combination is rarer than it sounds, and it’s precisely what premium renovation projects demand.
Steel’s strength-to-profile ratio makes this possible. Aluminium or timber frames need bulk to meet security standards. Hot-rolled W20 steel achieves structural integrity in a 32mm face width instead.
Add a 5-lever mortice lock with drop bolts as standard. It’s upgradeable to a multipoint locking system for PAS 24 compliance. The result is a frame that passes enhanced security testing while still maximising glazed area.
Why does this matter for home renovations? Planning constraints, heritage requirements, and aesthetic ambition all point in the same direction: less frame, more glass, no compromise on safety. Fabco’s West Sussex manufacturing facility produces bespoke configurations that meet this brief directly.
Why Certified Security Standards Matter in Premium Steel Glazing
Security certification isn’t just paperwork. For premium renovation projects, it’s the difference between a door that looks secure and one that’s been independently proven to resist real-world attack.
PAS 24 is the UK’s benchmark standard for enhanced security performance in doors and windows. Products must pass physical tests including lever attacks, drill attacks, and attempts to manipulate the locking hardware. Insurance providers and mortgage lenders increasingly recognise PAS 24 compliance as evidence of genuine protection.
Why does material choice matter?
Because security performance starts with the frame itself. Fabco’s hot-rolled W20 steel sections have a strength-to-profile ratio that most alternative materials simply can’t match at equivalent sightline widths. The frames are TIG welded at every critical joint – a process that produces stronger, cleaner bonds than mechanical fastening.
Door hinges are manufactured from heavy-gauge steel, then fixed directly to frame and sash. Window hinges are TIG welded to the frame from inside for a cleaner finished product.
Fabco’s PAS 24 compliant specification builds on this structural foundation by adding enhanced multipoint locking, security-tested hardware, and laminated glazing. That layered approach (strong material, precision engineering, then certified hardware) is exactly what independent testing is designed to verify.
Minimalist Glazing Ratios: The Engineering Challenge Behind Elegant Frames
A glazing ratio describes how much of a door / window’s visible face is actually glass versus frame. Slim frames mean higher ratios, but they also mean harder engineering problems.
Herein lies the tension; narrower frames require less material. Less material usually means less strength. That’s a real problem for security.
Getting slim sightlines, high glazing ratios, and certified security all working together is genuinely difficult.
Steel changes the equation. Its strength-to-profile ratio outperforms most alternative materials. Fabco’s W20 system proves this works: it achieves a 10mm sightline on a 32mm face width, producing exceptionally high glazing ratios without sacrificing the structural integrity that PAS 24 testing demands. Those narrow frames aren’t hollow profiles, they’re hot-rolled W20 steel sections, and every critical joint is TIG welded rather than mechanically fastened.
Glazing bars are fully welded into the frame structure, not clipped or bonded on top. This matters for security. Each bar becomes part of the inherent strength of the system.
The same slim profile also accepts 18mm slimline double-glazed units (a 4mm outer pane, 10mm krypton-filled cavity, and 4mm inner pane), achieving a whole-window U-value of approximately 2.0 W/m²K on the standard W20 system. Elegant proportions and thermal compliance aren’t mutually exclusive.
Security Certifications and Performance Specifications
Security performance in steel doors isn’t just about robust frames, it also comes down to certified specifications, tested hardware, and verified glass standards. Here’s exactly what Fabco’s security specification covers, with the concrete details that matter when specifying for a premium home renovation.
| Specification | Value | Notes |
|---|---|---|
| Frame Material Grade | Hot-rolled W20 steel sections with thicker gauge steel used in critical security areas | Hot-rolled steel provides inherently greater dimensional stability and resistance to forced entry than cold-formed alternatives. Frame movement over time is minimal, which matters for long-term locking performance. |
| PAS 24 Compliance | PAS 24 compliant specification available as an upgrade | PAS 24 is the UK construction industry’s recognised benchmark for enhanced security performance in windows and doorsets. The upgrade package includes enhanced multi-point locking, security-tested hardware, and enhanced laminated glazing. |
| Standard Door Lock System | 5-lever mortice lock with drop bolts – insurance-recognised specification | The 5-lever mortice lock meets insurance industry requirements, which can affect home insurance premiums. Upgrade to a multipoint locking system is available for higher security demands. |
| Security Glass Standard | Laminated security glass with interlayer bonding technology; toughened safety glass up to 5 times stronger than standard float glass | Laminated glass stays intact when broken because the interlayer holds fragments together, preventing quick forced entry. Both options are available within the W20 system. |
| Welded Construction Security Benefit | All critical frame joints TIG welded; glazing bars fully welded into frame structure – not clipped, glued, or surface-applied | TIG welding produces stronger, cleaner joints with greater fatigue resistance than mechanical fastening. Fully welded glazing bars become load-bearing structural elements, adding rigidity that supports security performance across the whole frame. |
| Fixing Specification | Corrosion-resistant stainless steel fixings used throughout installation | Non-rusting stainless steel fixings prevent long-term weakening at anchor points, maintaining structural security performance over decades rather than just at point of installation. |
Comparison: Security Rating vs. Frame Sight Lines Across Premium Steel Door Specifications
One question that comes up again and again for homeowners specifying premium steel glazing is this: does upgrading to a higher security certification mean accepting a chunkier frame? It’s a fair concern, because the whole appeal of steel windows is that 10mm sightline and the wall of glass it makes possible. The short answer is no, and Fabco’s W20 system is the clearest example of why. The table below maps security specification levels against achievable sightlines, glazing ratios, and thermal U-values, so readers can see exactly what each tier delivers and what it costs in frame width.
| Specification Level | Security Certification | Sightline / Face Width | Typical Glazing Ratio | Whole-Window U-Value | Key Hardware and Glass Spec | |
|---|---|---|---|---|---|---|
| Fabco W20 Standard | Entry-level security | Insurance-recognised 5-lever mortice lock with drop bolts | 10mm sightline / 32mm face width | Very high – slim frame maximises glass area | Approx. 2.0 W/m²K (B-rated WER) | Toughened safety glass; stainless steel fixings; TIG-welded frame joints |
| Fabco W20 PAS 24 Upgrade | Enhanced security – PAS 24 compliant specification | PAS 24 – UK benchmark for enhanced security performance; insurance-preferred | 10mm sightline / 32mm face width – no increase in frame width | Unchanged – same glazing ratio as standard W20 | Approx. 2.0 W/m²K (B-rated WER) | Enhanced laminated glazing with interlayer bonding; upgraded multipoint locking; security-tested hardware throughout |
| Fabco W20+ Standard | Entry-level security with premium thermal performance | Insurance-recognised 5-lever mortice lock with drop bolts | 10mm sightline – visually identical to W20 externally | Very high – identical slim profile to W20 | 1.3–1.4 W/m²K (A+-rated WER) – exceeds Building Regulations Part L | Toughened safety glass; krypton-filled 4/10/4 slimline double-glazed unit; stainless steel fixings |
| Fabco W20+ PAS 24 Upgrade | Enhanced security with premium thermal performance | PAS 24 compliant specification – highest combined security and thermal tier available | 10mm sightline – no frame width penalty for PAS 24 upgrade | Unchanged – maximised glazing ratio retained | 1.3–1.4 W/m²K (A+-rated WER) | Enhanced laminated security glass; multipoint locking system; security-tested hardware; krypton-filled 4/10/4 unit |
The key takeaway is that moving up the security tiers with Fabco’s W20 system (including to PAS 24) does not require any increase in the 10mm sightline or 32mm face width, meaning glazing ratios stay at their maximum regardless of the security specification chosen. Homeowners who also want the A+-rated U-value of 1.3–1.4 W/m²K can combine that with a PAS 24 security upgrade within the same visually identical frame.
Certified Security Steel Doors: Key Questions Answered
Deciding between certified security performance and maximised glazing ratios is one of the trickiest parts of specifying premium steel windows. Here are the questions renovation decision-makers ask most often, answered with specifics.
What does PAS 24 certification actually mean for steel glazing?
PAS 24 is a UK enhanced security standard that tests windows and doors against a range of forced-entry methods. For Fabco, achieving a PAS 24 compliant specification means upgrading to enhanced laminated security glass with interlayer bonding, a multipoint locking system, and security-tested hardware throughout. It’s recognised across the UK construction industry as the benchmark for enhanced security performance and satisfies Building Regulations Part Q for dwellings.
Does upgrading to PAS 24 security mean wider frames and less glass?
Not with Fabco’s W20 system. The sightline stays at 10mm and the face width stays at 32mm regardless of whether a standard or PAS 24 compliant specification is chosen. That means the glazing ratio remains at its maximum. Competing frame materials often require a wider profile to accommodate enhanced security hardware, but steel’s strength-to-profile ratio means Fabco avoids that trade-off entirely.
Can I get both PAS 24 security and an A+-rated U-value in the same frame?
Yes. Fabco’s W20+ system achieves a whole-window U-value of 1.3 to 1.4 W/m2K, which exceeds current Building Regulations Part L requirements, and can be combined with a PAS 24 security upgrade within the same visually identical 10mm sightline frame. The W20+ uses a krypton-filled 4mm outer pane, 10mm cavity, 4mm inner pane slimline double-glazed unit. Security and thermal performance are not mutually exclusive here.
What locking system comes as standard and what’s the upgrade path?
Fabco’s standard door specification includes an insurance-recognised 5-lever mortice lock with drop bolts. The PAS 24 upgrade replaces this with a multipoint locking system and security-tested hardware throughout. For context, a 5-lever mortice lock is the minimum level most home insurers require, so the standard specification already meets a practical security threshold before any upgrade is applied.
Does the W20 standard system meet Building Regulations for thermal performance?
The W20 standard system achieves a B-rated Window Energy Rating and a U-value of approximately 2.0 W/m2K. It meets current Building Regulations Part L for replacement windows via the WER rating route only. It does not meet Part L via the U-value route, since the current U-value limit is 1.4 W/m2K. Homeowners needing to satisfy Part L on a new-build or extension should specify the W20+, which achieves 1.3 to 1.4 W/m2K and satisfies both compliance routes.
How does Fabco protect steel frames from corrosion long-term?
Fabco applies hot-dip galvanising to British Standards as the primary corrosion protection method, followed by a durable powder-coated finish. Fixings throughout are corrosion-resistant stainless steel. The wet-glazing process uses RAL colour-matched silicone selected specifically for UV degradation resistance and colour-fastness. For coastal or marine environments, an optional enhanced protection specification is available, though exact details should be confirmed directly with Fabco for a specific project.
British Bespoke Manufacturing: Control, Accountability, and Premium Delivery
Getting security certification right takes precision. PAS 24 compliance with laminated glazing and multipoint locking demands exact tolerances at every stage. Subcontract the installation work, and you introduce variables that quietly undermine that precision.
Fabco’s model removes that risk entirely. Every project moves through a multi-step delivery process handled by directly employed project engineers, surveyors, installation fitters, and glazing engineers – all based at Fabco’s West Sussex manufacturing facility. No handoffs to outside contractors.
One dedicated project engineer acts as the single accountability point from the 3D laser survey through to final wet-glazing sign-off.
That same integration protects the minimalist aesthetic. Fabco’s 10mm sightlines are only achievable when fabrication, installation, and glazing are tightly coordinated. A misaligned frame or poorly applied silicone (even a millimetre out) shows against a profile that narrow.
The long-term value case follows directly. Steel windows installed with this level of precision and hot-dip galvanising to British Standards can perform for several decades. The premium upfront investment spreads across a significantly longer service life than most alternative frame materials.
Summary
Security certification, minimalist aesthetics, and British manufacturing aren’t competing priorities. In Fabco’s W20 system, they’re the same thing.
The 10mm sightline and 32mm face width are only achievable because hot-rolled steel has a strength-to-profile ratio no alternative material matches. That same structural strength supports PAS 24 compliant specifications with laminated security glass and multipoint locking, without widening the frame to accommodate them.
For premium renovation projects where certified performance and architectural authenticity both matter, Fabco’s integrated British manufacturing model makes a compelling case.
