Short answer. Japan's only official technical standard is the Cabinet Secretariat's non-binding Technical Guideline for Specified Temporary Evacuation Facilities (2nd edition, June 2024), written for public basement shelters able to hold people for about 2 weeks 1. There is no certification or approval scheme for shelter products 1. Detailed standards, including against nuclear attack, are under study 2.
What is the 2024 technical guideline?
特定臨時避難施設の技術ガイドライン（第２版）, first published in March 2024 and revised in June 2024 1. Its scope is the basements of new buildings that are used in peacetime as meeting rooms or car parks. The threat it addresses is blast and fragments from conventional bombs, shells and warheads 1. Such facilities are being built only in 5 municipalities of the Sakishima Islands in Okinawa 2.
What are its key points?
| Topic | Guideline |
|---|---|
| Length of stay | About 2 weeks |
| Floor area | About 2 m² per person plus circulation (100-300 people = 400-1,200 m²) |
| Entrances | At least 2, separated, with an antechamber and blast-resistant doors |
| Supplies | Storage for food, water (about 3 L per person per day) and supplies for 2 weeks |
| Toilets | About 1 per 20 people |
| Utilities | Emergency generator, water tank, protected air intakes |
| Structure | Reinforced-concrete exterior walls and slabs at least 30 cm thick |
Source: Cabinet Secretariat 1. Equivalent or better specifications are allowed 1.
These figures describe a public facility designed by professionals. They are not a recipe for a house, and this page gives no construction instructions. Any private project should be designed by a licensed engineer.
Is there certification for shelters or shelter products?
No. Japan has no certification or approval (homologation) scheme for shelter products 1. The March 2026 Cabinet policy says detailed shelter standards, including recommended technical performance, are being studied with the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and the Ministry of Defense, including shelters against nuclear attack 2. A product sold as meeting a "Japanese shelter standard" cannot point to an official certification today.
How does the guideline compare with household advice?
Its water allowance, about 3 litres per person per day 1, matches the household benchmark of 3 litres per person per day for drinking and cooking 3. For air supply and filtration, see /guides/shelter-ventilation and /guides/nbc-filtration; for what protection levels mean, /guides/protection-factor.
Frequently asked questions
Is the Japanese guideline mandatory?
No. It is a non-binding guideline for specified temporary evacuation facilities 1.
Does it cover nuclear weapons?
Its stated threat is blast and fragments from conventional weapons 1. Standards for shelters against nuclear attack are still under study 2.
Can I use the guideline for a private shelter?
It was written for public basement facilities 1. A licensed engineer can judge what applies to your site; see also the build a shelter page.
Sources
- 内閣官房 (Cabinet Secretariat) — 特定臨時避難施設の技術ガイドライン（概要）（第２版） — https://www.kokuminhogo.go.jp/pdf/hinan/240628_Guideline_gaiyou.pdf (accessed 2026-10-20)
- 内閣官房 (Cabinet Secretariat) — 緊急事態を想定した避難施設（シェルター）の確保に関する基本方針（令和８年３月31日閣議決定） — https://www.kokuminhogo.go.jp/pdf/hinan/260331shelter_hontai.pdf (accessed 2026-10-20)
- 農林水産省 (MAFF) — 知って備える 家庭備蓄のイロハ（aff 2026年3月号 特集） — https://www.maff.go.jp/j/pr/aff/2603/spe1_01.html (accessed 2026-10-20)
Turn this into action
Your plan for Japan, worked out for your household.
- Water, food and equipment counted for each person and pet
- The nuclear plants and zones around your home
- Phaenyx Safe: one tap to tell your people you are safe
Sources
- 内閣官房 (Cabinet Secretariat) · 特定臨時避難施設の技術ガイドライン（概要）（第２版） checked 2026-10-20
- 内閣官房 (Cabinet Secretariat) · 緊急事態を想定した避難施設（シェルター）の確保に関する基本方針（令和８年３月31日閣議決定） checked 2026-10-20
- 農林水産省 (MAFF) · 知って備える 家庭備蓄のイロハ（aff 2026年3月号 特集） checked 2026-10-20