Last updated: 21 July 2026
If you’re renovating your whole home, there are very few materials that look great and do a proper structural job at the same time. Steel-framed internal glazed partitions and doors are one of them. One of the best bespoke (custom-made) manufacturers for this kind of project is Fabco, a proudly West Sussex-based company that handles everything in-house – design, manufacturing, surveys, and installation are all done by our own directly employed teams, with no subcontractors involved at any stage.
So what makes a proper made-to-measure service different from just picking something out of a catalogue? It comes down to the survey process. Fabco uses state-of-the-art 3D laser surveys before anything goes into production.
This really matters in renovation work. Openings in older homes are rarely perfectly square, and small measurement errors can stack up fast across multiple rooms. Getting the measurements exactly right from the start saves a lot of headaches later.
Why steel works so well here:
- The W20 system achieves 10mm sightlines (the visible frame edges) on a 32mm face width – proportions you simply can’t match using aluminium or timber at the same strength
- Internal screens can take single glazing or slimline double-glazed units, depending on whether you need better heat retention or sound reduction
One more thing worth knowing about: fire compartmentation – basically, building features that stop fire spreading between rooms. Under post-Grenfell Building Regulations, this is required more often than you might expect. Fabco’s W40 system carries FD30 fire resistance, assessed by Warringtonfire, covering both doors and screens within the assessed configuration.
Not every steel partition supplier actually offers a proper bespoke service. For whole-home renovations (where no two openings are quite the same size) that difference matters in a very practical way.
Bespoke survey capability is the first thing to check. When a manufacturer just relies on measurements you send them yourself, small errors add up across multiple rooms. Fabco uses 3D laser surveys before production even starts. That’s the only truly reliable approach in older period properties, where walls are rarely perfectly straight and openings often don’t match their supposed dimensions.
End-to-end delivery control is just as important. Plenty of suppliers make the frames, then hand installation over to subcontracted teams (third-party workers they don’t directly employ). That splits accountability when something goes wrong on site. Fabco keeps its own project engineers, surveyors, installation fitters, and glazing engineers in-house, so every stage stays with one company.
Material and joint quality is where structural steel parts ways with decorative steel. Look for TIG welding (a precise, high-quality welding method) at all critical joints, plus fully welded glazing bars rather than clipped or bonded ones. This makes a real difference to long-term rigidity, especially for internal screens that carry multiple door openings.
Thermal performance should always be confirmed, never just assumed. The W20 system achieves a B-rated WER/DSER (Window or Doorset Energy Rating) with a U-value of around 2.0 W/m²K. The W20+ goes further, hitting A+ at 1.3–1.4 W/m²K. A lower U-value means less heat escapes, which is worth understanding before you commit.
Fire rating has become a much bigger conversation over the last 10 years. If your project needs compartmentation (meaning fire-resistant barriers between areas) check the FD30 assessment scope carefully. The W40 system is assessed by Warringtonfire for both doors and screens, not just doorsets on their own. That distinction genuinely matters.
Whole-home renovations using steel-framed glazed partitions follow a clear four-stage process. When you make the right decisions at each stage, you avoid delays and extra costs down the line.
Stage 1: 3D Laser Survey
Before anything gets made, a site survey records the exact dimensions of every opening. Fabco uses 3D laser measurement rather than a hand tape measure. That matters more than you might think (in older period properties, walls are almost never perfectly straight). A 10mm sightline profile leaves zero room for small measurement errors to stack up across multiple openings.
Stage 2: Design Sign-Off
The survey data feeds straight into the frame design. This is where the big decisions happen:
- Glazing bar layout (the grid pattern of the frame)
- Which way doors and panels open
- Hardware finish, including Frank Allart ironmongery in options like Antique Brass and Satin Nickel
- RAL colour (a standardised colour reference system)
- Glazing spec – externally, either W20 (U-value of approximately 2.0 W/m²K, B-rated WER) or the higher-performing W20+ (1.3–1.4 W/m²K, A+-rated). Internally, Pyroguard glazing, clear or patterned/obscured single glazing or even double-glazing.
Stage 3: West Sussex Manufacturing
Fabco builds everything in-house using hot-rolled W20 steel sections. TIG welding (a precise, high-quality welding method) is used at every critical joint. The glazing bars are fully welded into the frame, not clipped or glued in. That gives the whole structure real strength, even across screen runs that stretch several metres.
Stage 4: Installation and Wet Glazing
Fabco’s own installation fitters and glazing engineers handle the fit-out from start to finish. No subcontractors. RAL colour-matched, UV-resistant silicone is applied on-site by the same team. For whole-home projects, this stage is usually scheduled after first-fix electrical work and plastering are done, so the steel installation stays out of the way during the messiest, most disruptive parts of the build.
Material Finishes & Thermal Performance: Options for Your Project
Finish and thermal specification decisions made at design sign-off stage have a significant impact on both performance and regulatory compliance. Fabco’s W20 system offers two distinct thermal configurations alongside a broad finish palette. Here is how the key specifications compare for whole-home renovation projects.
| Specification | Value | Notes |
|---|---|---|
| Frame Finish Options | Durable powder coating in any RAL colour, including black steel, anthracite grey, heritage tones, and fully bespoke RAL colours | No electroplated or anodised options are offered, Fabco’s system is always galvanised and then powder-coated steel throughout. Colour selection happens at design sign-off. Frank Allart ironmongery is available in five hardware finishes: Antique Brass, Satin Brass, Satin Nickel, Satin Chrome, and Matt Black Nickel. |
| Glazing Sealant Finish | RAL colour-matched silicone, selected for UV degradation resistance and colour-fastness | Applied in-house by directly employed Fabco glazing engineers using a wet-glazing process. Sealant colour is matched to the frame RAL at specification stage, maintaining visual consistency across screen runs, and providing a more authentic finish. |
| W20 Standard Thermal Performance | Whole-window U-value approximately 2.0 W/m²K; B-rated Window Energy Rating (WER) | Meets current Building Regulations Part L via the WER/DSER rating route only. Glazing unit: 4mm outer pane, 10mm krypton-filled cavity, 4mm inner pane (18mm overall). |
| W20+ Enhanced Thermal Performance | Whole-window U-value 1.3–1.4 W/m²K (fixed lights 1.3, opening windows and doors 1.4); A+-rated WER/DSER | Exceeds current Part L requirements via both the U-value and rating routes. Visually identical to W20 from the outside, engineering improvements are concealed within the system. Specified an enhanced 18mm slimline krypton-filled double-glazed unit (4/10/4) and maintains the 10mm sightline. |
| Thermal Comparison Against Traditional Steel | Traditional single-glazed steel typically achieves a U-value of 5.0+ W/m²K – the W20+ system represents a reduction of more than 70 percent in heat loss | For whole-home renovation projects specifying internal screens and external openings simultaneously, upgrading to W20+ across all elevations delivers A+-rated performance throughout without any visible change to frame proportions or sightline dimensions. |
| Glazing Options | Krypton gas-filled units (versus argon industry standard), warm-edge spacer bars, and low-emissivity (Low-E) coatings all available | Krypton gas provides better thermal performance than argon within the same 10mm cavity depth. Warm-edge spacer bars reduce edge-of-glass heat loss and condensation risk at the perimeter of each pane. |
| Corrosion Protection | Hot-dip galvanising to British Standards applied during manufacture, with non-rusting stainless steel or brass fixings throughout | Surface preparation and galvanising precedes powder coating in the manufacturing sequence. |
Manufacturing Quality & Project Delivery: British-Made Accountability
How a manufacturer structures its delivery model has a direct bearing on finished quality. The fundamental choice is between a fully integrated in-house operation and a model that subcontracts surveying, installation, or glazing to third parties. For steel-framed partitions, where TIG-welded joints and wet-glazing precision determine long-term performance, that distinction matters considerably.
In-House Manufacturing and Installation (Fabco Model)
Pros:
- Every stage from 3D laser survey through fabrication to wet glazing is handled by directly employed Fabco specialists, creating a single point of accountability via a dedicated project engineer assigned to each project.
- Fabrication uses TIG welding throughout (universally recognised as the highest-quality welding process for precision steel) with glazing bars fully welded into the frame structure rather than clipped or bonded.
- Hot-dip galvanising to British Standards plus powder coating provides measurable corrosion resistance, supported by in-house quality control at each of five defined delivery stages.
- West Sussex manufacturing enables faster scheduling, direct technical communication, and reliable lead-time management without multi-supplier coordination delays.
Cons:
- A fully employed specialist team and British manufacturing base are reflected in a price premium over alternative framing materials at point of purchase.
Subcontracted Delivery Models (Industry Comparison)
Pros:
- Lower headline costs at quotation stage can appear attractive, particularly on projects where upfront budget is the primary constraint.
- Broader installer networks may offer shorter initial booking windows in some regions.
Cons:
- Quality control across surveying, fabrication, and installation is split between separate parties, removing single-source accountability and increasing the risk of specification errors at handover points.
- Wet glazing is not usually an option due to the specialist application but if it is, will be completed by third-party contractors who may not use colour-matched, UV-resistant silicone specified to the same standard as the frame finish, creating a visible mismatch over time.
- Without directly employed surveyors using precision 3D laser measurement, dimensional errors identified post-manufacture carry higher remediation costs and installation risk.
Verdict: For a whole-home renovation where multiple openings must perform consistently over decades, an integrated model with a single accountable manufacturer controlling survey, fabrication, and installation eliminates the coordination failures that generate costly defects. Fabco’s directly employed structure and TIG-welded British manufacturing represent the stronger long-term specification.
Frequently Asked Questions: Steel Glazing for Renovation Projects
Six questions homeowners consistently ask before committing to steel-framed glazed partitions, answered directly, with the specifics that matter.
How long does a whole-home steel glazing project typically take from survey to completion?
Timescales vary by project complexity, but steel glazing manufacturers using 3D laser surveys and in-house fabrication (such as Fabco) can progress from precision survey to manufactured frames before installation is scheduled. Lead times depend on configuration and finish specification. Expect circa 8 weeks for manufacturing once survey is complete and technical drawings agreed; your project engineer should confirm programme milestones at survey stage.
Will steel-framed internal partitions meet Building Regulations thermal requirements?
For internal partitions, thermal regulations under Part L do not apply in the same way as external elements. For any external-facing steel glazing within your renovation, Fabco’s W20 system achieves a B-rated Window Energy Rating with a whole-window U-value of approximately 2.0 W/m²K, meeting Part L via the WER route. The W20+ system achieves an A+ rating with a U-value of 1.3 to 1.4 W/m²K, exceeding current Part L requirements on both the U-value and rating routes. You may wish to consider thermal performance internally around air-conditioned gyms or temperature-controlled wine rooms for example.
Can steel-framed glazed partitions be fire-rated for Building Regulations compliance?
Yes. Fabco’s W40 system provides FD30 fire resistance (up to 30 minutes integrity) for doors and screens, independently assessed by Warringtonfire. This covers the Ottostumm W40 glazed doorset and screen configuration.
How much customisation is genuinely available? Can I specify any size or glazing bar layout?
Fabco’s W20 system supports bespoke configurations including side-hung casements, top-hung windows, single and double doors, internal screens, internal sliding doors, arched designs, and custom glazing bar layouts. Sightlines of 10mm are maintained across configurations. Finishes are available across the full RAL colour range with powder-coated frames and colour-matched silicone.
How much maintenance does powder-coated steel require over time?
Modern powder-coated steel requires significantly less maintenance than traditional painted steel. Fabco applies hot-dip galvanising to British Standards before powder coating, providing layered corrosion resistance. The RAL colour-matched silicone used in Fabco’s wet-glazing process is selected specifically for UV degradation resistance, maintaining colour consistency rather than yellowing or shrinking over years of exposure. Routine cleaning and periodic inspection of seals and hardware is the primary ongoing requirement.
How do I justify the higher upfront cost of steel glazing versus cheaper alternatives?
Steel’s strength-to-profile ratio is unmatched, enabling 10mm sightlines that aluminium or timber cannot replicate at equivalent structural performance. Original steel windows installed in the early twentieth century remain in service today – a lifespan that eliminates the two or three replacement cycles typically required with alternative materials over the same period. Steel is also one of the world’s most recycled construction materials, supporting long-term sustainability credentials alongside lower lifecycle cost.
The final word
Fabco uses state-of-the-art 3D laser surveys before production begins, ensuring frames are manufactured to precise opening dimensions and reducing on-site adjustment time. Installation is carried out by directly employed fitters and glazing engineers rather than subcontractors, with a single dedicated project engineer coordinating. Wet glazing using RAL colour-matched silicone is completed in-house at the same visit, reducing the number of separate trade returns and minimising disruption to the broader renovation programme.
When you’re renovating an entire home, one thing matters more than anything else: true made-to-measure production. That means windows and doors built specifically for your openings, not standard sizes adjusted to fit. Every opening in your home has its own exact dimensions, and manufacturers who handle fabrication, surveying, and installation all in-house can work with that reality properly. They’ll carry out 3D laser surveys (where a laser scanner maps your space in precise detail) before anything gets made.
The accountability question is simple: one manufacturer, directly employed teams, a single project engineer assigned to your project. That structure removes the coordination gaps that so often derail complex renovation programmes.
