Steel Frame Systems (SFS) broadly split into two types: infill walling, which fits between an existing primary structural frame, and standalone systems, which provide the complete structure themselves. Choosing correctly impacts programme, cost, and structural performance significantly.
The Two Main Approaches
At Basframes, we offer both infill and standalone SFS solutions — and our design team will always recommend the most technically and commercially efficient system for your specific brief, rather than defaulting to a one-size-fits-all solution.
SFS Infill Walling — What It Is and When to Use It
Infill walling is used where a primary structure — typically a reinforced concrete or structural steel frame — already provides the load-bearing skeleton. The SFS infill system fills the voids between floors and columns, creating a non-load-bearing external wall that supports cladding, brickwork, and other external finishes while resisting wind loads at each storey.
Infill SFS is the standard specification for high-rise commercial and residential developments across the UK — it is fast to install, lightweight (reducing dead load on the primary structure), and compatible with all major cladding systems including brick slip, rainscreen, render, and glazing. Basframes' infill walling system is designed to work with any primary frame specification and can be installed concurrently with other trades to maximise programme efficiency.
- The primary structural frame (RC or steel) is already specified or under construction
- The building is mid-rise or high-rise (typically 4+ storeys)
- You need lightweight, non-load-bearing external walling
- The façade involves brick, rainscreen, render, or curtain wall cladding
- Programme requires concurrent installation with other trades
Standalone Steel Frame Systems — What They Are and When to Use Them
A standalone system — also called a full-build or stick-build LGSF system — provides both the structural frame and the wall framing in a single, integrated solution. There is no separate primary structural frame — the cold-formed steel sections themselves carry all loads, including vertical gravity loads, lateral wind loads, and floor loads.
Standalone systems are ideal for low-to-mid-rise residential and commercial buildings where speed, cost, and sustainability are priorities. Basframes' standalone steel frame system supports buildings up to eight storeys, and can incorporate floating floor chipboard slabs or Lewis deck floors with screed finish for excellent acoustic and structural floor performance.
- Residential housing, apartments, hotels, or student accommodation
- Low-to-mid-rise buildings up to 8 storeys
- Projects where programme speed and off-site manufacture are priorities
- Developments where sustainability credentials are important
- Self-build or smaller-scale commercial projects
Panellised Systems — A Fast-Track Hybrid
For projects where maximum speed is the priority, Basframes can also supply a panellised LGSF solution. Rather than stick-building sections on site, full wall panels are factory-assembled to precise dimensions and delivered to site ready for craning into position. This approach dramatically reduces on-site labour, minimises programme risk from weather, and can reduce the overall construction programme by 20–30% compared to traditional methods.
Panellised systems are increasingly popular for housing developments, student accommodation blocks, and modular hotel projects where repetition and programme certainty are critical.
Side-by-Side Comparison
| Factor | SFS Infill Walling | Standalone System |
|---|---|---|
| Primary structure required? | Yes — RC or steel frame | No — SFS is the structure |
| Max storeys | Unlimited (non-load-bearing) | Up to 8 storeys |
| Best application | Mid/high-rise commercial & resi | Housing, apartments, hotels |
| Programme impact | Concurrent with primary frame | Fastest — all-in-one system |
| Sustainability | High — lightweight, recyclable | Very high — minimal waste |
Making the Right Choice for Your Project
The right choice between infill and standalone depends on your building type, storey count, programme requirements, and budget. Contact the Basframes team for a free technical consultation — we'll assess your brief and recommend the most appropriate system with indicative pricing. You can also browse our completed projects and ongoing projects to see both systems in action.
Not Sure Which System Is Right for You?
Our technical team offers free consultations to help you select the right SFS approach for your project.
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