The same house comes under different rules on how many people it may take, and needs different fire equipment, depending on what it is used for. Here is what an AI found in earlier articles for a single-storey 4LDK house (four bedrooms plus a living-dining-kitchen) with a total floor area of 145.04 m². The model opens with a free account. The AI used the tools it calls over MCP (check_space for the lodging rules, the floor area per person and the fire alarm).
1. How many, by use
| Use | Rule | In this house |
|---|---|---|
| A private lodging (minpaku), let whole | 3.3 m² per guest of the space guests occupy | 39 in 129.06 m² |
| A private lodging (minpaku), the host living in | 3.3 m² per guest of the space guests occupy | 14 in 47.52 m² |
| A simple lodging | No limit by floor area once the guest rooms reach 33 m² | No limit, 47.52 m² of guest rooms |
| An inn or hotel | Each guest room 7 m², 9 m² with a bed | Bedroom 2 (8.64 m²) is too small |
| A staff dormitory (Regulations on Dormitories Attached to Businesses) | 2.5 m² per sleeper, one toilet cubicle per 15 | 18 by the bedrooms, 15 by its one cubicle |
| Lodging for technical interns | 4.5 m² per sleeper | 7 |
| A group home for people with disabilities | One person per bedroom, 7.43 m² without its storage | All four bedrooms meet it |
2. The automatic fire alarm
| Use | Use under the Fire Service Act | At 145.04 m² |
|---|---|---|
| A share house | Item (5)(b) | Not needed (under 500 m²) |
| A minpaku, the whole house | Item (5)(a) | Needed (regardless of floor area) |
3. What they show
- Floor area is not the only limit. As a staff dormitory, the bedrooms hold 18, but the house’s one toilet cubicle limits it to 15. A simple lodging has no limit by floor area; other rules, such as the number of toilets and washbasins, set it.
- The rooms counted change the number. Let whole as a private lodging, the house’s 129.06 m² of guest space allows 39 guests; with the host living in and only the four bedrooms let, its 47.52 m² allows 14.
- The use changes the fire equipment. A share house under 500 m² needs no automatic fire alarm, but the same house let whole as a minpaku needs one regardless of floor area.
4. The articles
- How many guests can this house take?
- A house as a company dormitory: how many can live there?
- A house as a group home for people with disabilities
- A house as a share house: are extinguishers, an automatic fire alarm and exit signs needed?
5. How to ask an AI
If this house (as drawn) is a private lodging, how many guests may it take let whole, and with the host living in and only the bedrooms let? Tell me which rooms you count.
6. What this does not cover
- Not checked: the 180-day limit on minpaku, local ordinances, a change of use under the Building Standards Act, and the ordinances on the number of toilets and washbasins.
- In the end, check with the public health centre, the fire station and the building authority.
