BAS Frames formed all external walls and window openings in SFS around a hot rolled steel frame at Morasha Jewish Primary School in Finchley N3, clad externally in CP board — the complete external envelope delivered in under 3 weeks in 2018.
The main structure was built in hot rolled steel (HRS). Our scope was the infill: every external wall around that frame, every window opening formed within it, and CP board sheathing across the outside.
Why HRS and SFS work well together
Pairing a hot rolled steel primary frame with light gauge SFS infill is one of the most efficient combinations available on a fast-track building.
The HRS frame carries the building. The SFS carries only the façade — cladding, sheathing, insulation and wind load — which means it can be far lighter, and installed by a small team without craneage once the primary frame is up.
The two trades also follow each other closely. The infill can begin as soon as a bay of primary steel is complete, rather than waiting for the whole frame.
An early dry envelope, and what it unlocks
The real value of this approach shows up in what happens after we leave.
SFS infill with CP board sheathing produces a dry envelope quickly. There is no mortar to cure and no water introduced into the building. The moment the sheathing and membrane are on, the interior is protected and every following trade can start — mechanical and electrical first fix, drylining, screeds, finishes.
On a blockwork build, those trades wait. They wait for the walls to go up at the pace mortar allows, and then they wait for the building to dry. On a school with a fixed handover tied to a term date, that waiting is the whole risk.
3 weeks for the full external envelope
The entire external wall construction, including window openings and CP board cladding, was completed in under 3 weeks, on time and within budget.
It was a straightforward project, and we would describe it that way. Not every job is a technical challenge — some are simply a matter of a well-understood system, an experienced crew and a clear scope, executed without incident. On a live school site, that is exactly what a client wants.
Working on a live school site
School projects run to dates nobody can move. A handover slips past the start of term and the client has a building they cannot use for months, whatever the contract says.
That shapes how the work is planned. Materials arrive in sequence rather than in bulk, because a school has no laydown area to spare. Noisy operations are set against the timetable. And the method itself has to be predictable — a 3-week programme has no float to absorb a surprise.
Light steel infill suits that environment because so little of it is weather-dependent or time-dependent. There is no curing, no drying, and no wet trade whose progress a cold week can halt.
Project facts
- Client: Private client
- Location: Morasha Jewish Primary School, Finchley, London N3 1NR
- Scope: SFS infill to all external walls, window openings formed, CP board external cladding
- Primary structure: Hot rolled steel by others
- Year: 2018
- Duration: Under 3 weeks
Building a school or nursery to a term-date handover? See our SFS infill walling system, compare SFS infill against blockwork, or send us your drawings.
