Amendment to the Building Standards Act: Balancing decarbonization with the preservation of values that Japan must protect

Director of Zeroboard Research Institute, Director of Global Sustainability Standards Board (GSSB)

Tomoo Machiba

Not many people will realize that the revised Building Standards Act came into effect this month (April 2025). The Building Standards Act was originally established in 1950 with the aim of "protecting the lives, health, and property of the people, thereby contributing to the promotion of public welfare," and it stipulates minimum standards for buildings to prevent collapse in the event of a disaster and protect human lives. *1)

The aim of this revision is to strengthen energy-saving measures in the construction sector, which accounts for approximately 30% of Japan's Energy consumption, in order to achieve the decarbonization targets of carbon neutrality by 2050 and a 46% reduction in greenhouse gas (GHG) emissions by 2030 (compared to fiscal 2013). In principle, compliance with energy-saving standards (insulation grade 4 or higher and primary Energy consumption grade 4 or higher) *2) will be mandatory for all new residential and non-residential buildings (including extensions and renovations), and these are scheduled to be raised to the ZEH standard *3) by 2030. *4)

This may sound like good news, as it means that decarbonization is finally on the way in the Energy-inefficient housing sector, but it also presents some challenges. The most important change in the amendment is the review of the "Special Exception No. 4." Article 6, Paragraph 1, Item 4 of the law stipulated that when a small wooden building is designed by an architect, inspection of structural regulations, etc. could be omitted, but this time, two-story wooden buildings and single-story buildings over 200m2 (in other words, most ordinary homes) will no longer be subject to this omission. *5)

Figure: Changes to the scope of the No. 4 special exception and the Contents of the documents to be submitted *6)

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Recently, an increasing number of people are buying old or vacant houses and renovating them to continue living there or open businesses. However, these are now classified as "existing non-compliant buildings," and the majority of repairs and alterations to one or more of the main structural elements (walls, pillars, floors, beams, roofs, and stairs) require the submission of a confirmation application before construction, just like new construction. *7) For example, even if an old staircase is too steep and you want to make it less steep, you must thoroughly insulate and reinforce the entire building to meet the standards. Furthermore, energy conservation increases the weight of the building, making it even more difficult to ensure structural safety. Even if an old house is sturdy, it is a considerable hurdle to create blueprints and prove its earthquake resistance, as it was built based on the carpenter's intuition and with seismic isolation in mind.

As a result, only minor repairs will be made and the houses will be left to decay, or demolished and new buildings will be built, going against the national and local government efforts to utilize vacant houses. This will mean that only cultural assets will remain, and Japan's regional townscapes and farming and fishing village scenery that inbound tourists love will be lost. I am in favor of decarbonizing the entire housing stock, but I would like the government to consider making exceptions for buildings with long-term value, such as classic cars, and to expand subsidies for insulation renovations and earthquake reinforcement costs.

In a similar case, the revised Food Sanitation Act, which came into effect in June 2024, requires pickle Manufacturing to require a business license, and requires standards such as separating processing facilities from residences, introducing lever-operated or automatic faucets, and installing windows and screen doors in accordance with HACCP *8) , which are causing the disappearance of pickles made by local elderly people that were popular when sold at roadside stations and other places. The tightening of regulations was caused by a mass food poisoning incident caused by O157 in 2012, in which eight people died from overnight pickled Chinese cabbage Manufacturing by a manufacturer in Sapporo, and there is no point in applying it to most pickles that are fermented for a long time *9) .

While the objectives of such policies are noble, there are countless cases where the implementation design has had significant negative impacts in other ways (the recent debate over the "1.03 million yen barrier" is one example). Even in the area of decarbonization, concerns about the destruction of landscapes and the risk of natural disasters caused by the construction of solar power plants in mountainous areas have also tarnished the image of renewable energy in general. I believe that there are major issues surrounding the improvement of policymakers' capabilities, the thorough implementation of policy impact assessments, and the importance of Diet deliberations before bills are passed (as well as providing voters with clear and sufficient information to make a decision).

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＜Reference source＞

*1) Environmental and Energy Conservation Calculation Center, "Amendments to the Building Standards Act Coming in April 2025 | A Detailed Explanation of Six Amendment Points,"February 10, 2025: https://www.ceec.jp/column/kenchikukizyunho-2025-04　

*2) Logos Home, "What is a primary Energy consumption grade? An explanation of energy-saving standards, types of energy-saving homes, and even subsidies!", February 4, 2025: https://www.logoshome.jp/blog/house-performance/syouene-juutaku-toukyuu　

*3) Environmental and Energy Saving Calculation Center, "What are the ZEH standards? A professional explains the types, conditions, and benefits of obtaining a ZEH!", January 21, 2023: https://www.ceec.jp/column/zeh-standard ;

*4) Ministry of Land, Infrastructure, Transport and Tourism, "Regarding the Act to Partially Amend the Act on Improvement of Energy Consumption Performance of Buildings, etc. to Contribute to the Realization of a Carbon-Free Society (Act No. 69 of 2022),"December 26, 2024: https://www.mlit.go.jp/jutakukentiku/build/r4kaisei_shoenehou_kijunhou.html ;

*5) ANDPAD, "An easy-to-understand explanation of the reduction of the No. 4 special exception! What are the overview, changes, and impacts of the 2025 legal reform?", February 28, 2025: https://andpad.jp/columns/0087 ;

*6) Ministry of Land, Infrastructure, Transport and Tourism, "Changes to the No. 4 Special Provisions from April 2025 (planned),"October 2023: https://www.mlit.go.jp/common/001500388.pdf

*7) Ministry of Land, Infrastructure, Transport and Tourism, Housing Bureau, "Construction Confirmation Procedures for Large-Scale Renovations of Wooden Detached Houses,"January 14, 2025: https://www.mlit.go.jp/common/001766698.pdf

*8) Japan Food Hygiene Association "What is hygiene management using HACCP?": https://www.n-shokuei.jp/eisei/haccp_a.html ;

*9) Asahi Shimbun, “A-Stories: Pickle Crisis – Will rice accompaniments disappear?”, November 2022: https://www.asahi.com/rensai/list.html?id=1664