BB103 / BB104 area schedule calculator and worked examples
BB103 sets gross internal area per pupil for mainstream schools; BB104 sets it for SEN and AP. The area schedule is the maths the ESFA expects to see; without it the bid is incomplete.
BB103 mainstream formula
Primary: approximately 4.0 to 5.0m² per pupil GIA (varies with FE size). Secondary: approximately 6.5 to 7.0m² per pupil. Plus playing field and external standards [source: BB103, verified 2026-06-24].
BB104 SEN and AP
BB104 area runs significantly above BB103 mainstream per pupil because of sensory, hygiene and therapy spaces. For a 60-place SEN unit the area requirement is typically 12-20m² per pupil depending on the cohort profile [source: BB104, verified 2026-06-24].
Worked example: 420-place primary expansion
Adding 210 places at 5.0m²/pupil GIA implies 1,050m² additional GIA. Add roughly 12% for circulation and 8% for plant and toilets, total approximately 1,275m² of new build. Cross-check against playing-field standard for the post-expansion pupil number.
What the ESFA accepts as evidence
An area schedule signed by a chartered architect referencing BB103 or BB104, with the gross internal area per use class clearly tabulated and totalled.
How the fee-builder emits the schedule
The fee calculator's pupil-place slider drives a scope-day adjustment that lets the architect produce the schedule inside the Stage 1 fee. For complex sites add £1,500-£3,500 for additional iteration.