A school’s fire equipment: how many detectors in a classroom? Extinguishers, hydrants and exit lights, checked with your AI

Start from the primary school model (free sign-up). A school is item (7) of the table appended to Japan’s fire service order (消防法施行令別表第一). Unlike a restaurant or a hospital, much of its equipment is needed only once the building is large, and a usual floor needs no exit lights. In this article, in the members’ primary school floor, your AI checks the drawing against the rules. It ran the same tools an AI calls over MCP. Every figure and number below comes from that run.

1. The floor and where the extinguishers go

Plan of the school floor with the extinguishers — Four classrooms to the north, a central corridor, the science room, the music room, the toilets and the stair hall to the south; two extinguishers along the corridor’s north side, and the walk from the boys’ toilets’ south-east corner to one

The floor is 36.5 × 18.8 m = 686.2 m² to the outer walls’ centrelines: four classrooms (72 m²), a science room, a music room, toilets and a stair hall, along a central corridor.
Take this floor as the ground floor, with the way in, of a school of three storeys, each the same (an assumption): 2,058.6 m² in all.
In one change (edit_space), the AI put two extinguishers of 3 units each (an assumption) along the corridor’s north side, between the classrooms’ doors.
check_space finds nothing, before and after.

2. The equipment needed

Equipment	Needed	The rule
Extinguishers	Yes	300 m² in all or more (令第10条第1項第3号)
Automatic fire alarm	Yes	500 m² in all or more (令第21条第1項第4号)
Indoor hydrants	By the structure	700 m² in all or more (令第11条第1項第2号・第2項)
Exit lights	No	Only on basements, windowless floors and the 11th floor and up (令第26条第1項第1号・第2号)
Guide signs	Yes	Items (1) to (16) (令第26条第1項第4号)

The AI checked each with check_space. This floor is not windowless (fireWindowless: 43.92 m² of windows and the like that open to the outside, more than a thirtieth of the floor, 23.24 m²).
An item (7) building needs a fire prevention manager with 50 people or more (令第1条の2第3項第1号ハ). They are the teachers and staff and the pupils together (消防法施行規則第1条の3): this floor’s four classrooms alone hold 120 pupils at 30 a class. With 500 m² in all or more, the manager is of class A (甲種, 令第3条第1項).

3. Indoor hydrants change with the structure

The 700 m² for indoor hydrants is doubled or tripled by the structure and the finishes (令第11条第2項).

Structure	Finishes	Line	Indoor hydrants
Fire-resistant	Flame-retardant	2,100 m²	Not needed
Fire-resistant	Other	1,400 m²	Needed
Quasi-fire-resistant building	Flame-retardant	1,400 m²	Needed
Other	Other	700 m²	Needed

At 2,058.6 m² in all, the school needs no indoor hydrants if it is fire-resistant and finished in flame-retardant materials: just under 2,100 m².

4. The detectors in the classrooms

With fireAlarm, the AI counted differential spot heat detectors room by room (fire-resistant, ceilings of 3 m).

Room	Floor	Class 2	Class 1
Classroom 1	72.0 m²	2	1
Classroom 2	72.0 m²	2	1
Classroom 3	72.0 m²	2	1
Classroom 4	72.0 m²	2	1
Science room	80.0 m²	2	1
Music room	65.6 m²	1	1
In all		11	6

A class 2 detector covers 70 m², a class 1 one 90 m² (fire-resistant, ceilings under 4 m: 消防法施行規則第23条第4項第3号ロ). A classroom of 72 m² takes two of class 2, or one of class 1.
An item (7) building’s corridors need no detectors but on a basement, a windowless floor or the 11th floor and up (規則第23条第6項第3号). The toilets and the stair hall are not counted here.

5. The extinguishers

Structure and finishes	A unit covers	The building	This floor’s share
Fire-resistant, flame-retardant finishes	400 m²	5.15	1.74
Other	200 m²	10.29	3.49

The units are the total floor over 200 m², or over 400 m² if fire-resistant and finished in flame-retardant materials (消防法施行規則第6条第1項・第2項). This floor’s share is the floor as drawn (697.3 m², to the outer walls’ outer faces) over the same.
Two of 3 units give this floor 6: enough for its share either way. Each other floor takes its own share.
The farthest point is the boys’ toilets’ south-east corner, a walk of 15.8 m to an extinguisher: every point is within 20 m (規則第6条第6項).

6. Exit lights and guide signs

An item (7) building needs exit lights only on basements, windowless floors and the 11th floor and up: none on this floor.
It needs guide signs. The classrooms cannot see the way in, so they cannot be left out (規則第28条の2第3項: no exit seen within 30 m).

Room	To the way in	Seen
Classroom 1	12.33 m	No
Classroom 2	21.37 m	No
Classroom 3	30.46 m	No
Classroom 4	39.56 m	No
Science room	13.07 m	No
Music room	21.77 m	No

7. How to use this

Draw your school (from a PDF of the drawings or photos too), and tell the AI its total floor, its structure and finishes, and its ceilings’ height.
Not checked: the upper floors and the building as a whole, the toilets’ and the stairs’ detectors, escape devices, sprinklers, other buildings such as the gym, flame-proofing of curtains and the like, and notifying the fire station.