Renovating in Japan: the April 2025 building-confirmation change and the separate asbestos survey rules

Why legal procedures can affect renovation cost in Japan

A quotation for physical work is only one part of a renovation plan. A regulated project can also require design work, an inquiry into the existing building, a building-confirmation application, an asbestos survey, records and reports. Those are different tasks carried out by different actors. They affect sequence and scope even where this page supplies no price for any of them.

The first distinction is between a building's size and the work proposed for it. The second is between building confirmation and asbestos control. The 2025 change did not turn every renovation of a two-story house into confirmation work. The asbestos reporting figures did not create a price below which asbestos can be ignored. A useful reading starts by keeping all four propositions separate.

Building confirmation is not a catch-all permit

Kenchiku kakunin (建築確認) is the Building Standards Act's pre-construction compliance review. Where Article 6 applies, the building owner submits the plan to a building official or a designated confirmation and inspection body. The review asks whether the plan conforms to the building-related provisions named by the Act. A successful review produces a confirmation certificate before work starts.

This page uses building confirmation instead of treating the procedure as a generic construction permit. The statutory process is not one discretionary license that absorbs every other approval, notification or local rule. Development permission, use-related controls, local ordinances and the asbestos systems have their own legal routes. A completion inspection and its inspection certificate also occur at a different stage from the certificate issued before work starts.

What changed on 1 April 2025

Article 6(1)(ii), in force on the verification date, names a building with two or more stories or a total floor area exceeding 200 square meters. The test does not depend on whether the frame is timber, steel or reinforced concrete. A building in this category is brought into building confirmation for the work listed in the opening words of Article 6(1), including a major repair and major remodeling.

Before 1 April 2025, the corresponding timber category used a different set of thresholds: three or more stories, floor area exceeding 500 square meters, height exceeding 13 meters or eaves height exceeding 9 meters. The change is why the Ministry names a two-story timber detached house as an example of a building newly affected when the proposed work also meets the statutory major-work definition.

A one-story building of 200 square meters or less sits in a different Article 6 category, and the large-work wording is not attached to that category in the same way. That observation is not a complete exemption. Additions, rebuilding, relocation, changes of use, designated areas and ordinances have their own routes and are outside this narrow comparison.

More than half of one kind of principal building part

The statutory word major does not mean expensive. A major repair is a repair to more than half of at least one kind of principal building part. A major remodeling applies the same more-than-half structure to remodeling. Article 2(v) lists the relevant kinds as walls, columns, floors, beams, roofs and stairways, while excluding the minor parts named in the article.

One kind is enough. More than half of the roof can therefore matter without combining roof, floor and wall work into one grand percentage. The comparison is not half the rooms, half the budget or half the visible surfaces. The Ministry's examples measure walls by area, columns and beams by number, floors and roofs by horizontal projected area, and stairways by number on the story being examined.

The same material distinguishes a repair, which restores a part in roughly the same position, shape, dimensions and material, from a remodeling that replaces it with a different material or specification. It also shows work on finishes alone and several other arrangements outside the large-work category. Those examples explain a method; they do not classify a plan not shown in the Ministry document.

Structural work can also raise a different set of questions about an older building. The separate guide to Japan's earthquake building standards explains the 1981 line, existing non-conformity and the documents named in the real-estate disclosure rules without evaluating any building.

The existing-building condition survey guideline

Existing buildings carry a history. A confirmation application for later work may need evidence of what was built, when later work began and which rules applied at that point. The Ministry's Existing Building Condition Survey Guideline gives a first-class, second-class or timber architect acting within the statutory scope, or a designated confirmation and inspection body, a published route for organizing that history.

The fifth edition, published in September 2026, begins with available records, including the inspection certificate. It then identifies the relevant point in time, uses a site investigation to examine the existing building and records the result in a form that can support a confirmation application. The Ministry states that the earlier guideline for a building without an inspection certificate was integrated into this guideline on 1 April 2025.

The guideline is not building confirmation itself, and this page does not turn it into a universal inspection duty for every renovation. It is published assistance for examining existing conditions when an addition, rebuilding, relocation, major repair, major remodeling or change of use is being considered. Missing drawings and certificates can therefore be a process issue before any physical work is priced.

That records problem can be especially visible in an older vacant property. A separate guide covers the statutes surrounding an akiya without listing, valuing or recommending a property.

The asbestos survey is a separate system

Building confirmation examines a construction plan against building-related provisions. The asbestos rules address materials that will be disturbed by demolition, alteration or repair. A project can engage both systems, one of them or neither, depending on facts that are not determined by the other system.

The Ordinance on Prevention of Hazards Due to Asbestos requires a pre-work investigation of the materials in the part affected by the work. The prescribed route begins with documents and a visual survey. Where that route cannot determine whether asbestos is present, the ordinance provides for analysis or for treating the material as containing asbestos and applying the required protective measures.

For building work starting on or after 1 October 2023, the national qualification rule requires the survey to be carried out by a person within the specified qualification classes, subject to the limited exceptions in the regulation. The detached-house surveyor class is limited to detached houses and the inside of apartment units. A title alone should not be read beyond the qualification class attached to it.

The asbestos ordinance and the Air Pollution Control Act also create records, explanations, site display and reporting duties. Their wording assigns duties to specific actors: a business, a prime contractor, an ordering party or a self-performing party. Calling all of them the owner would erase distinctions written into the statutes.

The two national systems also start their three-year record periods at different events. Article 3(7) of the asbestos ordinance measures its survey-record period from completion of the survey. Article 16-8 of the Air Pollution Control Act regulation measures its record period from completion of the construction work. A statement that records are kept for three years is incomplete without that starting point.

One million yen and 80 square meters are reporting thresholds

The two figures printed in national guidance determine when a survey result must also be reported. They do not determine whether the pre-work survey exists. Work below a reporting threshold remains within the survey, record and site-handling rules unless a provision supplies a separate exception.

The law and regulation also address contract splitting. Work divided into two or more contracts with the same contractor is treated as one contract for the published threshold test. The building-demolition test uses area; the building-alteration and repair test uses contract value. Reversing those two measurements changes the rule.

The actors and the documents belong to different systems

The table is a map of roles named in the statutes and national guidance. It is not a project checklist and does not reassign any legal duty. The exact actor differs between the occupational-safety ordinance and the air-pollution statute, which is why the asbestos column keeps more than one label.

How the systems can meet in one renovation

The building-confirmation question asks what kind of building is involved and whether the proposed work falls into a statutory work category. The existing-building guideline helps a professional organize the condition and legal history of what is already there. The asbestos question asks what materials will be disturbed and which survey, record, display and reporting duties follow.

One project can put those routes beside each other. That does not merge them. A finding that building confirmation is not required does not remove the asbestos survey. A report under an asbestos system does not establish that building confirmation is required. The sequence matters because both systems contain steps that occur before physical work begins.

This is also why a renovation budget cannot be read from a cost-per- square-meter table alone. The regulated work, the available records, the need for professional investigation and the existence of reportable asbestos work can alter the process. None of those facts can be supplied by a national overview of an unseen building.

What this page does not decide

This page does not decide whether any project is a major repair or major remodeling, whether more than half of a principal building part is affected, whether a building complies with current or earlier law, whether material contains asbestos, or whether a notification or report is owed. It gives no estimate, design, survey, analysis, removal method, product, contractor ranking or route to a renovation service.

The national sources do not cover every prefectural or municipal ordinance. Nor does the page examine project contracts, liability, disputes, subsidies or tax relief. A building official or a designated confirmation and inspection body decides confirmation matters within its authority. A qualified asbestos surveyor deals with the materials within the scope of that qualification. The relevant prefecture, designated city and Labour Standards Inspection Office administer their reporting systems.

Sources

The four statutes and regulations below were read through e-Gov API version 2 with asof=2026-09-15. The Ministry pages and PDFs were read on the same date. Reference English in this guide is not an official translation; the Japanese text controls.

A note on the operator

SHINWA CREATIVE, K.K. is a welding and metalwork company in Miyagi Prefecture. Renovation work can overlap with services offered in the construction market, so this page offers no work, names no method, product or contractor, and carries no referral or affiliate link.

We sincerely appreciate every reader who has taken the time to explore this guide. We hope it makes Japan's renovation rules clearer and easier to navigate.