SFS Wall System: What It Is and How DogWall Ultra Takes It Further

SFS, or Steel Frame System, is a widely used method for building non-load-bearing external walls in commercial and multi-storey residential construction across Scandinavia and Western Europe. Cold-formed light gauge steel studs are fixed between floor slabs, insulation is placed between and over the studs, an air barrier membrane is applied to the external face, and a cladding subframe carries the external cladding panels. The result is a thin, lightweight, dry-construction wall that outperforms masonry on programme speed, weight, and usable floor area. It is the modern standard for commercial external wall construction.

The problem is not the system. The problem is how it is procured.

The Problem with Traditional SFS Procurement

A complete SFS wall assembly involves four to eight separate suppliers. Framing from one manufacturer. Insulation from another. Air barrier membrane from a third. Cladding subframe from a fourth. Cladding panels from a fifth. Window reveal detailing improvised on site by a specialist SFS subcontractor.

Each supplier is responsible only for their component. Nobody is responsible for the interfaces between them. When something fails, whether a thermal bridge appears, moisture gets in, or a cladding panel comes loose, each supplier points to the others. Establishing liability becomes a dispute rather than a resolution.

The window interface compounds this further. Detailing the reveal between the window frame, the wall build-up, and the external cladding is the most technically demanding part of any SFS wall. In traditional SFS construction it is resolved on site, improvised from drawings, by the installing subcontractor. Errors here are common and expensive to find once cladding is applied.

This is not a materials problem. It is a coordination and procurement problem. And it is the problem DogWall Ultra was designed to solve.

DogWall Ultra: The Complete SFS Wall System from One Manufacturer

DogWall Ultra by SIMPLEX Technologies is a factory-configured, flat-pack SFS wall system. One order covers everything needed to build a complete non-load-bearing external wall: SFS frame, Rockwool insulation, air barrier membrane, cladding subframe, and cladding panels. Every component is manufactured together, pre-cut to the specified dimensions, and delivered to site as a single configured kit. Window openings are projected in at the factory stage to the exact dimensions specified at order.

One supplier replaces four to eight. One warranty covers the complete system. General labour can install the kit without a specialist SFS subcontractor. There is no on-site cutting or sizing.

How DogWall Ultra Goes Together: The 4 Steps

Step 1: SFS Frame

The factory-manufactured SFS frame is the structural backbone of the wall. Cold-formed steel C-sections and tracks are CNC-manufactured to the exact floor-to-ceiling height and bay dimensions of the project. The frame arrives on site ready to fix directly between the floor slabs, with window opening positions already built in. No on-site cutting, no sizing adjustments.

Step 2: Wind Barrier Board

Once the SFS frame is fixed, a gypsum-based wind barrier board is installed across the external face of the frame. This closes the wall off completely, providing rigidity and protecting the insulation layer behind it from wind and weather. At this stage the wall assembly is structurally complete and weathertight, ready for the facade subframe and cladding to follow.

Step 3: Insulation and Windows

The wall is insulated from the inside, filled between the SFS studs. Because the frame and window openings are designed together as one system, the insulation fits precisely without on-site trimming and the windows drop straight into the pre-configured openings. The interior face of the wall at this stage is already complete.

Step 4: Facade Subframe and Cladding Panels

The final layer begins with the facade subframe, fixed to the SFS frame through the wind barrier board, creating the ventilated cavity between the board and the external cladding. Subframe fixes in to precise pins which are engineered in SFS frame. SIMPLEX panels are then fixed to the subframe across the full facade. The panels hang into position and the wall is complete. The same elevation simultaneously shows the finished cladding on the left and the board layer ready for panels on the right.

Cladding Finish: Full Design Freedom

DogWall Ultra is not a fixed product. The cladding finish is fully configurable across the SIMPLEX panel range.

Options include fibre cement panels with hidden fixing systems, metal cassettes, composite panels, and many more. The architectural result is indistinguishable from a site-built SFS wall. The difference is in the procurement and installation process, not the finished appearance.

Panels are configured at the time of order. Window positions, opening sizes, insulation thickness, and panel type are all specified upfront and factored into the factory configuration. What arrives on site is the wall, not the components of a wall.

Beyond aesthetics, DogWall Ultra can be configured to meet various project-specific requirements including fire safety, acoustic performance, and thermal insulation standards — all within the same single-source system.

What DogWall Ultra Means for Each Stakeholder

For developers: One order, one delivery, one point of accountability. No managing four separate building envelope suppliers. No interface disputes if something fails. A wall that costs less to build and causes fewer problems across the project lifecycle. In a 6-storey commercial building with a 300-metre perimeter, the thinner SFS wall assembly compared to masonry recovers 540 m² of usable floor area, worth €1,350,000 at €2,500/m².

For contractors: No specialist SFS subcontractor required. No on-site cutting. No multi-supplier delivery coordination. General labour can install the complete kit. Programme moves faster because the wall arrives as a configured system, not as raw components.

For architects: A system-tested wall assembly with a single specification document and a single warranty. The window interface is pre-engineered to drawing, not improvised on site. Full cladding design freedom within the SIMPLEX panel range. Single point of technical contact for the complete wall.

SIMPLEX Technologies: External Wall and Facade Specialists

SIMPLEX Technologies are specialists in non-load-bearing external wall systems and ventilated facade solutions, with over 300 completed projects across the Baltics, Scandinavia, and the UK.

If you have a project where the external wall system is under consideration, we are happy to advise on the right approach and prepare a technical proposal.

📧 simplex@simplex.lv 📞 +371 28603704 🌐 simplex.lv