Overview of Japanese Laws and the Building Code

Unlike the US, where building codes begin as proprietary model codes that are adopted by local jurisdictions, in Japan the building code is a series of interconnecting national laws. For this reason, it’s important to have and understanding of how Japanese laws are structured and work.

Hierarchy of Laws

The “building code” is a collection of laws that apply to building design, construction, professional and construction contracting services, etc. Japan’s laws have a distinct hierarchical system, where the Constitution is the highest law, followed by some treaties and laws legislated by the National Diet, followed by orders issued by the Cabinet or Ministers. Where provided by these laws, local governments may establish additional requirements within the scope of the National laws.

The table below illustrates this hierarchy of laws and provides important keywords:

Constitution

The Constitution was established by the Diet and became effective in 1946. It is the top law in all the land, and no law or treaty can be affected in conflict with it.

It really doesn’t have a daily impact on the building code other than as a fountainhead for the authority of the various assemblies to create law through legislation and for executives to create law through enforcement orders (regulation).

Further reading:

• The Constitution of Japan (日本国憲法, Constitution, 1946)
• National Government Organization Act (国家行政組織法, Act No. 20 of 1948)

Treaties

Treaties are international agreements between Japan and other sovereigns, through the National Diet. While treaties are international agreements, the Diet does enact laws in keeping with the treaties that apply within the nation. Note that no treaty or other law in opposition to the Constitution may be enacted.

There aren’t any major international treaties that practically relate to the Japanese building code.

Acts

The Constitution empowers the National Diet as the sole legislative body of state, to create and enact statutory laws; these are usually translated to “act”. These laws are effective throughout the whole country.

Japan has a central form of government, where the power generally resides with the national government. The Constitution does provide for “local autonomy,” which has had several different interpretations over the last several decades. However, the Diet will enact laws that broadly apply to the entire country but devolves authority to local governments as appropriate to administer their local regions.

Further Reading:

• Local Autonomy Act (地方自治法, Act. 67 of 1947)

Orders

Orders (命令めいれい) are laws not enacted through the Diet but by administrative organs of the Japanese Government.

Unlike the US, where the Administration is a separate, coequal branch of Government, Japan has a unitary parliamentary system. According to the Constitution, the Prime Minister is selected by the Diet from among its two Houses. The Prime Minister forms a Cabinet of Ministers (i.e. The Cabinet), which are the heads of the various Ministries.

As the administrative arm, their duty is to enforce the laws enacted by the Diet. The National Government Organization Act provides for these administrative organizations: the Cabinet was well as the individual Ministers, to issue Orders that have the force of law, but only within the scope permitted by the underlying Act.

There are two types of orders:

• Cabinet Orders (政令), developed at the Cabinet Level, these are often called Enforcement Orders (施行令しこうれい)
• Ministerial Orders (省令), developed by the respective Ministers, these are often called Enforcement Rules (施行規則しこうきそく)

Cabinet Orders provide additional requirements and details on the enforcement of Acts and Treaties, while Ministerial Orders do the same, or provide additional details and procedural requirements regarding the Cabinet Orders. Neither type of order may create law that is outside the scope of the enforcement orders or underlying acts. Typically, the underlying Act or Cabinet Order will make a statement, e.g. “as provided for in the Cabinet Order or Ministerial Order”, etc.

The order of precedence: Acts are greater than Cabinet Orders, which are greater than Ministerial Orders. But they do not conflict; rather, the subsequent orders merely provide additional details or fine procedural requirements.

Another type of order is a Bureau Order 庁令ちょうれい, which is an ordinance established by the external bureau of a Ministry or Agency. Currently, there are no such orders affecting the building code laws or design and construction practices.

NOTE: There used to be Imperial Orders (勅令ちょくれい), however these no longer have legal effect after the Constitution came into effect (1947). According to the Constitution, the Japanese Emperor is a symbolic figure, who derives his position from the will of the people, who are the sovereign power. There aren’t any Imperial Orders relevant to the building code.

Local Governments

Somewhat like the nation-level government, local governments generally have a legislative assembly body and an executive who enforces laws. There are two levels of local government, both having these entities:

Like the national-level, these entities can create laws, but their scope is limited to their geographic jurisdiction, and their authority is limited to that specified by the National-level laws, or as devolved by the National government.

Prefectural laws have precedence over municipal laws, but they generally do not conflict. Rather, Prefectural law supports a broader suite of services, generally where greater resources are required.

Ordinances and Rules

Laws that are enacted by a prefectural or municipal assembly are called 条例 (ordinances). These are laws that only apply within a given Prefecture, and they may not contradict the Constitution or National Laws. Nor can they create law outside the scope provided for by National law.

While the Prime Minister and other Ministers are not directly elected by the people, Governors (知事) and Mayors (市長・村長) are. Nevertheless, these officials are tasked with executing the laws enacted by local assemblies. While doing so, they are empowered to create enforcement rules (規則), having the force of law, within the scope provided by the underlying ordinance.

Ordinances and rules are limited regionally, whether prefectural or municipal. Generally, these relate to safety or procedural requirements, or zoning considerations, etc., that arise given the local conditions, climate, population needs, etc.

Documents that are Not Laws

There are other types of documents commonly referenced in and around the building code, or in design or construction contexts, but that do not have the force of law, per se.

Notices

There are several types of notices (通知つうち), which are documents that provide additional information, or explanations about things in a law.

Ministerial Notifications

The most important and commonly encountered such notices are the Ministerial Notification (告示こくじ). These are notices published by Ministries that provide the public with additional information that is often necessary for a complete understanding of the law.

For example, Ministry of Construction Notification 1454 of 2000 (平１２建告示第１４５４号) is an important Ministerial Notification that provide important details necessary for structural engineers and architects to be able to calculate design wind pressures, as required per the Enforcement Order for the Building Standards Act, Art. 87.

NOTE: While ministerial notices are not law, are quite a number that are closely linked with various provisions of the Japanese building code, thus they do require respect and careful consideration.

Other Documents

There are other documents such as Technical Guidance (技術的助言ぎじゅつてきじょげん), Directives 通達つうたつ and Instructions 訓令くんれい, which are typical documents of advice or policy, that original from a higher level of government to a lower level. These may be issued to provide guidance or policy on how to interpret or enforce various aspects of the law. Regardless, these do not generally have the public in mind as the intended audience.

Summary Example

Here is an example showing an Act enacted by the Diet, whose requirements are subsequently detailed in related Cabinet and Ministerial Orders, and for work in Tokyo prefecture, for example, the Prefectural Ordinance is also provided.

The Act applies to all prefectures, as does the Cabinet and Ministerial Orders, but the Prefectural Ordinance only applies in Tokyo prefecture.

The Japanese Building Code

Equipped with the preceding understanding, we can finally explain that there is no single Japanese building code. Rather, the Japanese building code is a collection of various laws and regulations. So how does one figure out what those laws are?

First, if you learn nothing else, note that the Building Standards Act (建築基準法), formally known as Act No. 201 of 1950, is the major starting point. But there are many other laws that designers and contractors need to know and follow.

Package Law Collection Books

There are several publishers that package the key laws and ministerial notifications into one or two books, which are usually published on an annual basis to capture updates. Below are five different versions that contain the same collections of laws. The differences are not in the laws, but how the publishers format the text, the size of the books, etc.

Example Building Related Law Collections

MLIT (Inoue)	TAC	Sogo	Nikken	Inoue

Below are several links for the various versions illustrated above. Please be careful to find the latest version:

• 基本建築関係法令集法令編 and 告示編
• TAC　建築基準関係法令集
• 総合資格学院　建築関係法令集
• 日建学院　建築基準法関係法令集
• 井上学院　建築関係法令集

The TAC, Sogo and Nikken versions are generally geared towards Architectural license exam test takers. They structure the data and provide cross-references to help aid the reader quickly access the information. The blue version (edited by MLIT and published by Inoue) includes two volumes with the second containing several hundred Ministerial Notifications.

Online Versions (Free)

For those on a budget, the good news is that all these laws and ministerial notifications are public documents and can be found for free online. National laws such as Acts, Cabinet Orders and Ministerial Orders can be found on e-Gov Law Search: https://laws.e-gov.go.jp/

Ministerial Notifications and other ministry documents can be found on those respective ministry websites. Local documents (prefectural or municipal) likewise are available on the respective websites.

English Versions

The Ministry of Justice has tentative translations for some of the major Japanese laws; these are hosted on their Japanese Law Translation website: https://www.japaneselawtranslation.go.jp/en/laws. Unfortunately, many laws have not been translated and those that have been translated may not be the most current version. So please be careful.

There is a print English version called "The Building Standard Law of Japan (2016)", published by the Japan Building Center (日本建築センター). Unfortunately, this translation is over 10 years old and covers dated materials.