Three things set the specification: space per pupil from Building Bulletin guidance, acoustic performance that lets teaching happen, and ventilation that keeps CO2 down through a full lesson. A modular classroom that meets all three is a permanent-quality teaching space that happens to be built in a factory. Here are the numbers and the choices.
Building Bulletin area guidance is the accepted starting point for mainstream rooms, with SEN guidance working from smaller classes and higher space per pupil. These are guideline areas for feasibility; your pupil profile sets the final schedule.
| Room | Typical occupancy | Guideline area |
|---|---|---|
| General teaching classroom | 30 pupils | 55 to 62 m² |
| Small-group room | 4 to 8 pupils | 12 to 20 m² |
| SEN class base | 8 to 10 pupils | 50 to 60 m² |
| SEN hygiene / care suite | n/a | 12 to 16 m² |
| Calm / sensory room | 1 to 3 pupils | 9 to 16 m² |
Add cloakrooms, storage, WCs and circulation on top: a "60 m² classroom" project is usually an 80 to 100 m² building. Our drawn layouts, like the twin classroom block and the classroom suite with WCs, show how that plays out.
School acoustics standards control indoor ambient noise and reverberation in teaching spaces, which in a modular building drives the glazing specification, wall and floor build-ups and acoustic ceilings; it is the difference between a classroom and a cabin with desks. Ventilation guidance for schools limits CO2 concentrations in occupied classrooms, which sets the ventilation strategy: openable windows plus mechanical support sized to the occupancy. For SEN settings we also design for the sensory environment: glare control, calm colour palettes, robust but soft-feel finishes and acoustic separation between class bases and calm rooms.
Both ranges build to the same standards. The steel cabin ranges (Classic and Plus) give a robust, low-maintenance, relocatable building, useful where the classroom may move or the setting is hard on its buildings. The timber frame ranges (Standard and Premier) feel closest to a permanent school building inside and out, with the Premier tier carrying the higher thermal specification and external cladding options; parent-facing independent settings usually choose it. SEN groups often combine a robust shell with a calm interior specification, which either range supports.
The programme is planned backwards from the term you need the room: design and approvals first, 8 to 14 weeks of manufacture with groundworks in fenced, supervised windows, then delivery and crane set in a half term or holiday, commissioning, and handover before the first morning bell. The full service is described on the school buildings page.
About Cabinworx. Cabinworx designs, supplies and installs steel and timber frame modular buildings across the UK, from welfare and canteen blocks to classrooms, nursery rooms and sanitary buildings. Steel cabins come in our Classic and Plus ranges, timber frame in Standard and Premier, and every building is delivered and installed on a prepared base by our team.
School buildings: design, supply & installTell us the rooms you need, pupil numbers and term dates. We come back with a layout, a programme and a fixed quote, usually within two working days.