Change of Use for Former Government Buildings — Three Legal Walls and How to Break Through Them

Why Change of Use for Former Government Buildings Is Challenging

A change of use shifts what the Building Standards Act, the Fire Service Act and the seismic retrofitting act each require

When city halls are merged or relocated, municipalities consider putting the vacated buildings to other uses. Among national government buildings, more than half have passed 30 years since construction[4]. No national statistic gives the same share for local government buildings, so check your own buildings against the construction-year tables in your comprehensive public facility management plan.

Converting a former city hall into a welfare facility, an assembly hall or a hotel changes what three laws require:

1. Building confirmation for a change of use under the Building Standards Act (Article 87)
2. Whether fire protection equipment must meet the standards for the new use under the Fire Service Act (Article 17-3)
3. The effort duty, instructions and mandatory diagnosis for seismic diagnosis and retrofitting under the Act on Promotion of Seismic Retrofitting of Buildings

Confirmation is handled by the building official or a designated confirmation and inspection body, consent and inspection for fire protection equipment by the chief of the local fire department or fire station, and guidance and instructions under the seismic retrofitting act by the competent administrative agency. With three separate counterparts, check the conditions with each once you have candidate uses.

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Wall 1 — Building Standards Act Confirmation Application

Three conditions for confirmation, similar uses, the amendment promulgated in 2018, and buildings without inspection certificates

Three Conditions That Trigger Confirmation

When a building's use is changed so that it becomes a special building used for a purpose listed in column (i) of Appended Table 1, and the floor area used for that purpose totals more than 200㎡, the confirmation procedure applies. Changes between similar uses designated by Cabinet Order are excluded. When the work is finished, the owner notifies the building official instead of applying for a completion inspection[5].

Whether or not confirmation is needed, zoning restrictions under Article 48 and other rules apply when a building's use changes. When the building is an existing non-conforming building, which met the standards when built but not the current rules, Articles 27, 28, 35 and others also apply, except for changes between similar uses without major repair or remodelling and a few other cases[6]. Even when no change of use confirmation is required, the duty to comply with the law remains.

The Amendment Promulgated in 2018 Raised the Threshold from 100㎡ to 200㎡

The Act Partially Amending the Building Standards Act (Act No. 67 of 2018) was promulgated on June 27, 2018, with part of it taking effect on September 25 that year and the rest on June 25, 2019. To promote the use of existing building stock through changes of use, it removed the confirmation procedure for buildings of 200㎡ or less when their use is changed into a special building[7]. If the part being converted exceeds 200㎡, confirmation is still required.

Special Buildings in Appended Table 1

Column (i) of Appended Table 1 runs from category (1) to (6), and each includes "other similar uses specified by Cabinet Order". The Enforcement Order specifies child welfare facilities, etc. as similar to category (2); museums, art museums, libraries, bowling alleys, ski slopes, skating rinks, swimming pools and sports practice facilities for category (3); public baths, machiai, ryotei, restaurants and retail stores (excluding those of 10㎡ or less) for category (4); and film and television studios for category (6)[8].

Child welfare facilities, etc. include child welfare facilities such as nursery centres, as well as welfare facilities for the elderly, fee-based homes for the elderly, support facilities for persons with disabilities and welfare homes (Enforcement Order Article 19(1)). Offices are not listed in Appended Table 1, so a former city hall that stays in office use needs no confirmation under Article 87(1).

Similar Uses Exempt from Confirmation

Similar uses exempt from confirmation form 11 groups: theatres, cinemas and performance halls; public halls and assembly halls; clinics with inpatient facilities and child welfare facilities, etc.; hotels and ryokan; boarding houses and dormitories; museums, art museums and libraries; gymnasiums, bowling alleys, skating rinks, swimming pools, ski slopes, golf driving ranges and batting cages; department stores, markets and other retail stores; cabarets, cafés, nightclubs and bars; machiai and ryotei; and film and television studios. Some groups are excluded in Category 1 low-rise exclusive residential zones and certain other zones[9].

Offices belong to none of these groups, so converting a former city hall into a welfare facility or a shop is not a change between similar uses. Article 137-19 is a separate provision: it sets the similar uses for which Article 27 and others are not applied when an existing non-conforming building changes use, and it does not decide whether confirmation is needed.

Buildings Without an Inspection Certificate

The completion inspection rate, the number of inspection certificates issued in a fiscal year divided by the number of confirmations, was about 40% in FY1998 and about 90% in FY2016[10]. Buildings that never received an inspection certificate made up more than half up to 1999. When such a building is extended, altered or changed in use, the confirmation application must show that the existing parts complied with the law at the time of construction, and it is hard to tell whether the building is existing non-conforming or in violation[11].

These guidelines were merged into the Guidelines for Surveying the Current State of Existing Buildings on April 1, 2025.

A current-state survey is carried out by an architect or a designated confirmation and inspection body at the owner's request. It starts by checking whether an inspection certificate was issued for the most recent construction work. Even if the owner has lost the certificate, it can be confirmed by viewing the summary of dispositions or obtaining a certificate of register entries from the designated administrative agency. Without a certificate, a building confirmed by site survey to have complied with the law when the work began is treated as existing non-conforming; if the start date cannot be determined, the whole building must be brought into line with current law[12].

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Wall 2 — Fire Service Act Retroactive Application

When the new standards apply, Specified Fire Prevention Objects, conditions by equipment, fire department consent and notification

Which Standards Apply After a Change of Use

When a change of use means that fire protection equipment no longer meets the technical standards for the new use, the standards for the previous use apply in principle. However, the standards for the new use apply to equipment that already violated the standards before the change, to extensions, alterations and major repairs or remodelling specified by Cabinet Order that begin after the change, and where the new use is that of a Specified Fire Prevention Object[13].

Excluded from this principle are fire extinguishers and evacuation equipment, together with simple fire-extinguishing tools, automatic fire alarms in certain uses, earth leakage fire alarms, emergency alarm devices and systems, exit signs and guidance signs, and some others; these must meet the new standards. The extensions and alterations specified by Cabinet Order are those whose floor area totals 1,000㎡ or more, or half or more of the total floor area at the base date, and the major repairs or remodelling are those affecting more than half of the walls that are main structural parts[14].

What Are Specified Fire Prevention Objects?

Specified Fire Prevention Objects are department stores, inns, hospitals, underground malls and mixed-use buildings specified by Cabinet Order, together with fire prevention objects specified by Cabinet Order as entered by many people. The Enforcement Order lists categories (1) to (4), (5)(a), (6), (9)(a), (16)(a) and (16-3) of Appended Table 1[15].

A former city hall used as offices falls under category (15). Converting it into an assembly hall ((1)(b)), a hotel ((5)(a)) or a welfare facility ((6)) makes the new use a Specified Fire Prevention Object, and its fire protection equipment must meet the standards for the new use.

Conditions by Equipment

Examples of the standards after a change of use. Each has detailed conditions on how floors and floor areas are counted, so take the drawings to the local fire department.

Consulting the Fire Department and Notifying Installation

A building official or designated confirmation and inspection body confirming a change of use cannot give confirmation without the consent of the chief of the fire department or fire station with jurisdiction over the site, except for certain houses outside fire and quasi-fire prevention districts[16]. Before applying for confirmation, ask the local fire department about:

1. The Appended Table 1 category after the change of use
2. Which fire protection equipment must meet the new standards
3. Whether existing equipment can be kept
4. The documents needed for fire department consent

When fire protection equipment is installed, the owner notifies the chief of the fire department or fire station and has it inspected. This applies regardless of floor area to (5)(a), (6)(a)(1) to (3), (6)(b), and (6)(c) facilities that house or accommodate users; from 300㎡ of total floor area to (1), (4), day-use (6)(c) and others; and to (7), (15) and others of 300㎡ or more designated by the chief. Simple fire-extinguishing tools and emergency alarm devices are excluded[17].

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Wall 3 — Seismic Standard Compliance

The 1981 boundary, change of use and structural strength, categories under the seismic retrofitting act, reading diagnosis results

The 1981 Boundary

MLIT notes that many buildings built in or before 1981 were built under the so-called old seismic standards, before the standards were strengthened, and lack adequate seismic performance. It urges owners to start with a seismic diagnosis and to consider retrofitting or rebuilding if performance falls short[18]. The Enforcement Order treats buildings whose new construction began on or before May 31, 1981 as buildings of unclear seismic safety, excluding those that later underwent extension, major repair or similar work begun on or after June 1 that year and received an inspection certificate, and some others[19].

Change of Use and Structural Strength

The provisions applied when an existing non-conforming building changes use are Article 27, Article 28(1) and (3), Articles 29 and 30, Articles 35 to 35-3, part of Article 36, Article 48(1) to (14), Article 51 and others; structural strength under Article 20 is not among them[20]. The guide's summary table also lists structural strength (Article 20) as a provision with relaxation measures for extensions, alterations and major repairs or remodelling, and as not applied retroactively on a change of use[21].

Seismic diagnosis and retrofitting are asked of owners by the seismic retrofitting act below.

Obligations Under the Seismic Retrofitting Act

Seismic diagnosis is mandatory for buildings listed in prefectural or municipal seismic retrofitting promotion plans (buildings listed in safety confirmation plans), which include buildings such as hospitals and government offices whose use must be secured after an earthquake in the public interest, and buildings along roads named in the plans (Article 7). Owners of existing seismically non-conforming buildings of a certain size used by many people, such as schools, hospitals, assembly halls, department stores, offices and homes for the elderly (specified existing seismically non-conforming buildings), must endeavour to carry out seismic diagnosis and, where needed, retrofitting (Article 14). For those above a certain size used by unspecified large numbers of people, or mainly by people who need particular care in evacuation such as residents of homes for the elderly, the competent administrative agency may give necessary instructions when it finds that diagnosis or retrofitting has not been carried out, and may publish the fact if the owner does not comply without good reason (Article 15). Owners of other existing seismically non-conforming buildings must also endeavour to carry out diagnosis and retrofitting as needed (Article 16). Large buildings used by unspecified large numbers of people, such as hospitals, stores and inns, and large schools and homes for the elderly (large buildings requiring urgent safety confirmation) had to report diagnosis results by December 31, 2015 (Supplementary Provisions Article 3)[22].

The size thresholds by use are set by the Enforcement Order. Floor area is the total floor area used for that purpose.

The thresholds come from Article 6(2) and Article 8(2). Article 6 sets 2 or more storeys and 500㎡ or more for kindergartens and nursery centres, 2 or more storeys and 1,000㎡ or more for elementary schools and similar and homes for the elderly and similar, and 3 or more storeys and 1,000㎡ or more for offices, assembly halls, hotels, ryokan and others. Article 8 sets 2,000㎡ or more for homes for the elderly, hotels, assembly halls and others, 750㎡ or more for kindergartens and nursery centres, and 1,500㎡ or more for elementary schools and similar[2].

Reading Seismic Diagnosis Results

The seismic index of structure Is and the index of horizontal load-bearing capacity q divide the seismic safety of the main structural parts into three categories[3]. Wooden buildings are assessed with the seismic index Iw under Appended Table 1 of the same notice.

The earthquake meant here is a large one of intensity 6-upper to 7. In every category, unless a building was built illegally or left to deteriorate, a medium earthquake of about intensity 5-upper is not expected to cause collapse[23].

Reinforcement Methods Depend on Each Building's Diagnosis

For the main wing of its city hall, whose Is-value of 0.346 fell short, Shimoda City compared adding conventional steel braces inside the building, which keeps costs down but disrupts work severely and takes longer, with adding RC braces with embedded steel plates outside the building, which costs more but takes less time and affects the offices little. Because the concrete in columns and walls tested at 12 N/mm2, below the design standard of 18 N/mm2, and carbonation had progressed, the city said the decision on reinforcement had to be made with care[24].

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Breakthrough — Practical Strategies for Overcoming Three Walls

Conditions under the three laws by new use, the order of steps, and subsidies for seismic diagnosis and retrofitting

What the Three Laws Require by New Use

Leasing the building as offices is the only case with no change-of-use procedure. The effort duty under the seismic retrofitting act, however, depends on the building's use and size, not on whether it is converted.

The Order of Steps

1. Check whether the confirmation certificate, inspection certificate and drawings exist. If not, investigate following the guidelines for surveying existing buildings
2. Check the seismic diagnosis results (Is-value and q) and ask the competent administrative agency which category of the seismic retrofitting act applies
3. For each candidate use, identify its category in Appended Table 1 of the Building Standards Act and of the Fire Service Act Enforcement Order
4. Take the candidates to the building official or a designated confirmation and inspection body, and to the local fire department
5. If that use exceeds 200㎡, obtain confirmation and notify the building official when the work ends. Notify the installation of fire protection equipment and have it inspected

When works accompanying a change of use of an existing non-conforming building are split into two or more stages, and the designated administrative agency finds that the overall plan meets standards such as the split being unavoidable, the provisions of Article 87(3) are not applied until the last stage of work begins (Article 87-2)[7].

Subsidies for Seismic Diagnosis and Retrofitting

Under the Housing and Building Safety Stock Formation Program, a core program of the Social Capital Development Grant and the Disaster Prevention and Safety Grant, seismic diagnosis and reinforcement design of buildings receive 1/3 from the national government when a local government carries them out, and 2/3 from the national and local governments combined when a private owner does. For retrofitting, rebuilding or demolition of buildings used by many people (department stores of 1,000㎡ or more and similar), public buildings receive 11.5% from the national government and private buildings 23% from the national and local governments combined; for disaster response bases such as evacuation shelters, public buildings receive 1/3 from the national government and private buildings 2/3 from the national and local governments combined. Local governments' own subsidy schemes should be checked with the local government where the building stands[25].

Under the Act on Special Measures for Supporting the Sustainable Development of Depopulated Areas, 70% of the principal and interest on depopulation countermeasure bonds is covered by local allocation tax[26]. A municipality in a depopulated area should check through its sustainable development plan and bond procedures whether the bonds can fund the renovation.

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Case Study — Shimoda City Former Inouzawa Junior High School

The city's policy and construction timeline, and how the law treats converting a school into offices

Background

Shimoda City had been working on its new city hall since 2009. Because the city hall was an old-seismic-standard building in marked disrepair and stood in a tsunami inundation zone, rebuilding or relocation had been under consideration since 2009. After debate over several candidate sites, the city passed an ordinance in December 2017 fixing the Kawachi area as the new location. It later paused and re-examined the project in light of a newly published flood forecast for the Inouzawa River and the fiscal effects of the spread of COVID-19[24].

The Pivot — From New Construction to Renovation

In FY2021 the city carried out a safety survey of the existing city hall and a structural durability survey of Inouzawa Junior High School. At the September 2021 council session it amended the ordinance on the location of the city hall, keeping Kawachi as the site and moving the effective date to within 2026, and restarted the project aiming to complete the building in FY2025 and open in FY2026. The detailed surveys showed that the existing city hall had a high risk of collapse and needed more urgent action[27].

The existing city hall's Is-values were 0.346 for the main wing, 0.39 for the west wing and 0.402 for the annex, all short of adequate seismic performance. Finding the main wing hard to reinforce, the city decided to move office functions early into the Inouzawa Junior High School building after necessary renovation. The school building and gymnasium stand outside the tsunami inundation zone, were built to the new seismic standard, and are described as considerably sturdier than the existing city hall. On the other hand, the school building was 40 years old and the gymnasium 37, and the city noted that even renovation to extend their life would leave a limited service life[24].

The reasons and cost estimates for using the school, as given in the city's documents and press coverage:

• Location and structure. The school building and gymnasium stand outside the tsunami inundation zone and were built to the new seismic standard (early relocation policy)
• Cost. The estimate put renovation work for the school at about ¥580 million (2,934㎡ × about ¥200,000 per ㎡) and renovation design at about ¥20 million. For reference, the earlier new-build design estimate was about ¥500,000 per ㎡. The total project estimate was ¥2.8 to 3.2 billion in the revised plan, against ¥3.69 billion in the previous plan[24]. All of these are estimates as of February 2022, not actual construction costs
• Press coverage. With cost reduction and lower environmental impact in mind, the city decided to use the former Inouzawa Junior High School facilities as its new city hall

How the Law Treats Converting a School into Offices

Under the Building Standards Act, offices are not listed in Appended Table 1, so using a school as offices is not subject to confirmation under Article 87(1). Zoning restrictions under Article 48 and other rules still apply (Article 87(2)). Any part built as an addition goes through the procedure for construction, not for a change of use.

Under the Fire Service Act, schools are category (7) and offices category (15), and neither is a Specified Fire Prevention Object. Fire protection equipment may in principle stay under the standards for the previous use, but fire extinguishers, evacuation equipment, exit signs and some other items, as well as extensions, alterations, and major repairs or remodelling above a certain scale begun after the change, must meet the standards for the new use (Article 17-3).

Specified buildings under the barrier-free act include public health centres, tax offices and other government offices used by unspecified large numbers of people, and the same article also lists public elementary and junior high schools and others. The duty to meet the building accessibility standards when a use is changed to a specified building applies where that part's floor area totals 2,000㎡ or more[28]. Whether a change from a school to a government office falls under this duty should be checked with the competent administrative agency.

Timeline

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ISVD Perspective

The first thing to decide when converting a former city hall is its new use. Once the use is fixed, the statutes settle whether the Building Standards Act requires confirmation (Appended Table 1 and 200㎡), whether fire protection equipment must meet the new standards (whether it is a Specified Fire Prevention Object), and from what size the seismic retrofitting act imposes an effort duty or instructions.

Leasing the building as offices involves no change-of-use procedure. Converting it into a welfare facility or a hotel means checking the conditions under all three laws. Shimoda City turned a school building into its city hall, but only after setting out in its policy document the existing hall's seismic shortfall, the school's location and structure, and the cost estimates.

Gathering the inspection certificate and seismic diagnosis results before choosing a use lets you compare how many procedures each candidate use would add.

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Related Articles

Guide

Building Code Compliance for Closed School Reuse

Confirmation, fire compartments, smoke control and fire protection equipment for converting a closed school into a welfare facility, checked against the statutes

Guide

Selecting PPP Methods by Fiscal Capacity Index

Optimal solutions across five tiers from 0.3 to beyond 1.0

Guide

Cost Structure of Closed School Renovation

Unit cost assumptions by item, renovation costs from MEXT's case collection, and cost reduction strategies

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What to do next

Before changing the use of an old government building, review its records and condition and consult on the procedures for the intended use.

Ask the facilities team where records are held, identify missing documents and any additional survey needs, then consult the building and fire safety authorities.

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References

Building Standards Act (Act No. 201 of 1950) — e-Gov Legal Database (e-Gov)

Building Standards Act Enforcement Order (Cabinet Order No. 338 of 1950) — e-Gov Legal Database (e-Gov)

Fire Service Act (Act No. 186 of 1948) — e-Gov Legal Database (e-Gov)

Order for Enforcement of the Fire Service Act (Cabinet Order No. 37 of 1961) — e-Gov Legal Database (e-Gov)

Act on Promotion of Seismic Retrofitting of Buildings (Act No. 123 of 1995) — e-Gov Legal Database (e-Gov)

Enforcement Order of the Act on Promotion of Seismic Retrofitting of Buildings (Cabinet Order No. 429 of 1995) — e-Gov Legal Database (e-Gov)

Explanatory Guide on Relaxation Measures for Existing Buildings (4th Edition) — MLIT (2026)

Guidelines for Surveying the Current State of Existing Buildings (5th Edition) — MLIT (2026)

Enforcement of the Act Partially Amending the Building Standards Act (technical advice) — Director-General of the Housing Bureau, MLIT (2019)

Overview of the Building Confirmation and Inspection System — MLIT (2019)

Act on Promotion of Seismic Retrofitting of Buildings — MLIT Housing Bureau (2025)

Basic Policy for Promoting Seismic Diagnosis and Retrofitting of Buildings (MLIT Notice No. 184 of 2006) — MLIT (2025)

Support Measures for Seismic Retrofitting of Housing and Buildings (FY2026) — MLIT (2026)

Early Relocation Policy for the New City Hall — Shimoda City (2022)

New City Hall Construction — Shimoda City (2026)