Where can you open a trunk room? — use districts and Building Standards Act requirements

In short: whether you can open a trunk room (rental storage) is first narrowed by the use district. Under the Building Standards Act it is treated as a "warehouse," and in principle cannot be built in Category 1 and 2 low-rise residential districts or the Category 1 mid/high-rise residential district. An outdoor container that cannot be moved at will is a building under Article 2(1) of the Building Standards Act, and needs a confirmation application. If you convert an existing shop or warehouse and the portion used for that purpose exceeds 200 m², a change-of-use confirmation (Article 87) is required. Merely renting storage space needs no warehousing-business registration, but final feasibility turns on the use district, structure and fire equipment. Change-of-use confirmation and structural judgement are for an architect and a designated confirmation and inspection body; whether fire equipment is required is for the fire station with jurisdiction.

For owners who want to start a trunk room or rental storage on idle shops, warehouses or land, and for operators looking for premises, this article sets out how to choose the property and whether the use is permitted — from the Building Standards Act, the Warehousing Business Act and the Fire Service Act Enforcement Order, and the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) materials. Renting out storage space itself is not a licensed business, but whether the property can be used is a question of the building and the use district. The final check is made with an architect, a designated confirmation and inspection body, the fire station and the specified administrative agency with jurisdiction, together with our own property investigation.

Which use districts allow a trunk room?

Under the Building Standards Act, a trunk room is treated as a "warehouse" and is subject to use-district limits. The more a district is meant to protect housing, the harder a warehouse is to build.

Building restrictions within use districts are set by Article 48 and Appended Table 2 of the Building Standards Act. Warehouses become buildable from the more lightly restricted of the residential districts, and are widely buildable in commercial and industrial districts. In practice, whether container or indoor type, we treat the following three districts as ones where a trunk room cannot, in principle, be opened.

Feasibility (general framing)	Use district
In principle not possible	Category 1 low-rise residential / Category 2 low-rise residential / Category 1 mid/high-rise residential
Often possible (check)	Category 2 mid/high-rise residential / Category 1 and 2 residential / quasi-residential
Tends to suit	Neighbourhood commercial / commercial / quasi-industrial / industrial / exclusive industrial

Note that the "warehouse operating a warehousing business," which Appended Table 2 expressly restricts, differs from a trunk room (rental of storage space). Renting storage space is not a warehousing business, so that express restriction does not directly apply. Still, since the building itself is a "warehouse," the conclusion that opening one in a residential-exclusive district is difficult in practice does not change. How far it is permitted in which use district varies with the practice of the specified administrative agency (the local building official), so confirming with the specified administrative agency for the location before contracting is the sure route. Use districts can be checked on MLIT's "Real Estate Information Library" map.

How does the Building Standards Act treat indoor versus outdoor (container) types?

The indoor type — partitioning a room within a building to let — and the outdoor type — placing a container on the site — enter the confirmation process differently.

For the outdoor container type, first fix whether the container counts as a "building." MLIT holds that a container that cannot be moved at will falls, by its form and actual use, within the "building" of Article 2(1) of the Building Standards Act (Notice No. Kokujūshi 2174 of 6 December 2004, "On the treatment of buildings using containers"; Notice No. Kokujūan 5 of 26 December 2014, "On thorough measures against violations concerning buildings using containers." Accessed 17 September 2026.). Being a building, it must obtain a building confirmation and comply with structural strength, fire prevention and use-district rules. "It is just placed there, so it is not a building" is a misunderstanding.

	Indoor type (partition inside a building)	Outdoor container type
A building?	The existing building is a building	A container in continuous use counts as a building (Notice 2174)
Main points	Existing building's use and whether change-of-use applies	Container's confirmation, structure, fastening to foundation
Use district	Restricted as a warehouse	Same (in principle not in residential-exclusive districts)
Easy to trip on	Change-of-use confirmation (over 200 m²)	The "not a building" misunderstanding / foundation, structure

For container types, whether it is fastened to a foundation and whether the structural safety of stacking has been checked are also issues. Structural suitability is the field of an architect and a designated confirmation and inspection body. Property requirements for a warehouse premised on warehousing-business registration are set out in What are the conditions for a property that can be a commercial warehouse?; this article deals separately with storage-space rental, which needs no registration.

When you convert an existing shop or warehouse to a trunk room, is change-of-use confirmation required?

It can be. The dividing line is whether the floor area used as a trunk room (warehouse) exceeds 200 m².

Article 87 of the Building Standards Act applies the confirmation rules by analogy where a building's use is changed to a special building listed in Appended Table 1 of the Act (one whose total floor area for that use exceeds 200 m²). Because a warehouse is a special building, changing, say, a shop (a shop for retail business, etc., in Appended Table 1) to a warehouse over 200 m² requires a change-of-use confirmation. Below 200 m², confirmation is not needed, but the duty to comply with the Act's substantive provisions (evacuation, fire prevention, etc.) remains.

Conversion pattern	Change-of-use confirmation
Turning an existing warehouse into a trunk room (use stays "warehouse")	In principle not required, as the use does not change
Changing a shop/office to a warehouse (over 200 m²)	In principle required (Article 87)
The relevant use portion after change is 200 m² or less	Confirmation not required (but compliance with substantive rules is)

A change-of-use confirmation needs backing that the existing building was lawful when built (a completion inspection certificate, etc.). How to read a property when converting a used building without a completion inspection certificate into a welfare facility is set out in Can a used property without a completion inspection certificate be converted to a welfare facility?; the reasoning applies to trunk rooms too. Whether a change-of-use confirmation is required, and the design and structural judgement, are the field of an architect and a designated confirmation and inspection body. We organise the property's registration, whether it has a completion inspection certificate, and its current state, and connect this to the architect's judgement.

What is the minimum to prepare for fire safety, crime prevention and safety management?

A warehouse is regulated under the Fire Service Act as a use with fire risk. What is needed varies with scale and local ordinances.

In Appended Table 1 of the Fire Service Act Enforcement Order, a warehouse falls under item (14). Fire equipment such as extinguishers, automatic fire alarms and guide lights is required according to total floor area and structure. What is needed from what scale is for the fire station with jurisdiction to judge, and consultation before starting work is the key. On crime prevention and safety, prepare locks, lighting and cameras, ventilation to avoid condensation and mould, and rules (terms of use) to keep users from bringing in dangerous goods, cash or perishables.

Item	Where to check / what to prepare
Fire equipment (extinguishers, alarms, guide lights)	Fire station with jurisdiction (Fire Service Act Enforcement Order Appended Table 1, item (14) = warehouse)
Change-of-use, structure, evacuation	Architect and designated confirmation and inspection body
Crime prevention, ventilation, terms of use	Operator (locks, lighting, cameras, listing prohibited items)

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Note that a "certified trunk room" — where a warehousing business accepts deposits of goods for safekeeping (registration under the Warehousing Business Act required) — and a "rental storage space" that merely lets storage space (no warehousing-business registration required) are different things. The latter is a lease of real estate, and the business of renting out storage space itself needs no licence. But whether the property can be used is decided by the use district, change-of-use and fire matters covered above.

What costs are easy to overlook when estimating rent and yield?

Judge a trunk room by yield alone and you tend to miss the initial cost and the slow ramp-up in occupancy. Think not of gross yield but of costs and the vacancy period too.

Easy to overlook are the cost of change-of-use confirmation and design, the installation cost of containers, partitions, air conditioning and security equipment, the cost of fire equipment, and low occupancy right after opening (the time to reach full occupancy). Advertising to attract users, the effort of management and cleaning, and reinstatement or removal on exit build up as in any leasing business.

Cost / factor easy to overlook	Content
Confirmation / design cost	Change-of-use (over 200 m²) or new-build design and application
Installation cost	Containers, partitions, lighting, ventilation, cameras
Fire equipment	Extinguishers, alarms, guide lights (by scale)
Ramp-up	Assumed low-occupancy period until full
Operation / exit	Advertising, cleaning, reinstatement, removal

Because figures vary greatly by property and area, we do not assert a specific yield; we set out the breakdown of costs and how to think about vacancy risk. How to find business premises and the overall picture of investment are at Consultation on investment and business property, and property consultation for opening a business is at Consultation on business premises. Consultation is free of charge.

The division of roles is as follows. Property investigation, valuation, brokerage and the lease contract are handled by Yotsuba Real Estate Co., Ltd. (四葉不動産株式会社; licensed real estate agent, Tokyo Governor (1) No. 113304). Change-of-use confirmation and structural judgement are for an architect and a designated confirmation and inspection body; whether fire equipment is required, for the fire station with jurisdiction; the labour and social insurance of employees after opening, for a certified social insurance labour consultant — each engaged or consulted by you directly. These are independent business entities, engaged separately and directly by you. We neither pay nor accept referral fees or introduction commissions.

Frequently asked questions

Q. Do I need warehousing-business registration to start a trunk room (renting out storage space)?
A. A rental storage space that merely lets storage space is a lease of real estate and needs no registration under the Warehousing Business Act. Registration is needed for a "certified trunk room," where a warehousing business accepts deposits of goods for safekeeping. Even without registration, whether the property can be used is decided by the use district, change-of-use and fire matters. Check with the specified administrative agency and the fire station for each property.

Q. Can I place a container on vacant land in a residential neighbourhood and make it a trunk room?
A. If the use district is a Category 1 or 2 low-rise residential district or a Category 1 mid/high-rise residential district, a warehouse cannot, in principle, be built. Also, a container that cannot be moved at will is a building under Article 2(1) of the Building Standards Act (Notice 2174), needing confirmation and compliance with structure and fire prevention. It is not simply "placing it," so confirm the use district and the specified administrative agency's practice before contracting.

Q. Do I need change-of-use confirmation to convert an existing warehouse into a trunk room?
A. If the use is already "warehouse" and you keep using it as a warehouse, the use does not change, and change-of-use confirmation is in principle not required. Changing a shop or office to a warehouse over 200 m² requires change-of-use confirmation under Article 87 of the Building Standards Act. Even below 200 m², compliance with substantive rules such as evacuation and fire prevention is required. Confirm the need and the design with an architect and a designated confirmation and inspection body.

Q. Does a trunk room need fire equipment?
A. A warehouse falls under item (14) of Appended Table 1 of the Fire Service Act Enforcement Order, and extinguishers, automatic fire alarms, guide lights and the like are required according to total floor area and structure. What is needed from what scale is for the fire station with jurisdiction. Consulting the fire station before starting work avoids having to redo the work.

Sources (primary)

• e-Gov "建築基準法" (Building Standards Act) — Act No. 201 of 1950. Art. 2(1) (definition of a building); Art. 48 and Appended Table 2 (building restrictions within use districts); Art. 87 (analogous application on change of use — a special building in Appended Table 1 with over 200 m² for that use). Accessed 17 September 2026.
• MLIT "On the treatment of buildings using containers" — Notice No. Kokujūshi 2174 of 6 December 2004; Notice No. Kokujūan 5 of 26 December 2014. A container that cannot be moved at will falls within the building of Article 2(1). Accessed 17 September 2026.
• e-Gov "消防法施行令" (Fire Service Act Enforcement Order) Appended Table 1 — Cabinet Order No. 37 of 1961. A warehouse is item (14); fire equipment depends on total floor area and structure. Accessed 17 September 2026.
• e-Gov "倉庫業法" (Warehousing Business Act) — Act No. 121 of 1956. Art. 3 (a warehousing business requires MLIT registration). It covers commercial warehouses that accept deposits of goods for safekeeping; renting storage space is not that. Accessed 17 September 2026.
• MLIT Chubu District Transport Bureau "How to use a trunk room well" — the distinction between a certified trunk room, run by a Warehousing Business Act-registered operator accepting deposits of goods, and a rental storage space that lets storage space. Accessed 17 September 2026.

Whether a use is permitted in a given district and whether change-of-use is required vary with the practice of the specified administrative agency (the local building official) for the location; confirm with the agency before contracting, and change-of-use confirmation and structural judgement are carried out by an architect and a designated confirmation and inspection body. Whether fire equipment is required is judged by the fire station with jurisdiction; consult it before starting work. This article is general information and does not offer a legal determination or investment advice. Feasibility for a specific property depends on the judgement of the specified administrative agency, the fire station and an architect, and on our own property investigation. Property investigation, brokerage and the lease contract are undertaken by 四葉不動産株式会社 (licensed real estate agent); change-of-use confirmation by an architect and a designated confirmation and inspection body; fire matters by the fire station with jurisdiction; labour and social insurance by a certified social insurance labour consultant — independent business entities, engaged separately and directly. We neither pay nor accept referral fees.

About the author

Joji Uramatsu — licensed real estate transaction specialist (Tokyo Governor registration No. 293544) and administrative scrivener (registration No. 25087022). Representative Director, Yotsuba Real Estate Co., Ltd. (四葉不動産株式会社; real estate business licence: Tokyo Governor (1) No. 113304); Representative, 四葉行政書士事務所. Kohinata, Bunkyo, Tokyo, about five minutes' walk from Myogadani station. For a trunk-room property, the use district and the building's registration and completion inspection certificate go on the same table, sorting out first what to confirm with the architect and the fire station. Full profile: author page.