Singapore's household shelter standards: TRHS 2023 explained

Short answer. Singapore's Civil Defence Force (SCDF) publishes binding technical standards: the Technical Requirements for Household Shelters 2023 (TRHS 2023), which apply to all houses and flats, and the Technical Requirements for Storey Shelters 2021 ¹². They cover shelter size, wall and slab thickness, ventilation sleeves, the SCDF-approved steel door, and construction and commissioning ¹. Section 14 of the Civil Defence Shelter Act 1997 is their legal basis ⁵.

Which standards apply?

The Act requires every new house to have a household shelter "in accordance with the specifications" ⁵, and section 14 provides the legal basis for those specifications ⁵. The standards are therefore binding, not advisory.

What do the standards cover?

According to SCDF, the household shelter requirements deal with ¹:

• Shelter size;
• Wall and slab thickness;
• Ventilation sleeves;
• the light protective steel door, which must be an SCDF-approved model;
• construction and commissioning.

The exact dimensions and values are in the TRHS 2023 document itself ¹. Phaenyx does not reproduce construction values: design and structural work belong to a qualified engineer working from the official text.

How is compliance checked?

Two checks apply:

1. Approved doors. Shelter doors must be approved by SCDF ³.
2. Commissioning. Since 1 April 2023, shelter aspects go into the Building Plan and Structural Plan submissions to the Building and Construction Authority (BCA), and a commissioning application on completion verifies compliance ⁴.

Deviations from the requirements need an SCDF waiver ⁴. The approval steps are set out on Building a shelter in Singapore.

What do the standards mean for residents?

Residents do not design shelters, but some rules touch daily use. The Act forbids repairs or alterations likely to impair a shelter without the SCDF Commissioner's written permission ⁵. Keeping the door and ventilation sleeves working, and leaving ventilation openings partly uncovered in peacetime, protects what the standards built in; see Building a shelter in Singapore.

For the general principles behind shelter design, see What is a shelter's protection factor?, How much fresh air does a shelter need? and How does NBC air filtration work in a shelter?. These guides explain concepts; they do not replace the Singapore standards.

Frequently asked questions

Where can I read the TRHS 2023?

SCDF publishes the Technical Requirements for Household Shelters 2023 as a PDF ¹.

Does TRHS 2023 apply to HDB flats?

SCDF states that TRHS 2023 applies to all houses or flats ¹.

Can any steel door be used for a household shelter?

No. Shelter doors must be approved by SCDF ³.

Is there a separate standard for storey shelters?

Yes: the Technical Requirements for Storey Shelters 2021 ².

Sources

1. Singapore Civil Defence Force (SCDF) — Technical Requirements for Household Shelters 2023 — https://www.scdf.gov.sg/docs/default-source/cd-shelter-(docs)/technical-requirements-for-household-shelters-2023.pdf (accessed 2026-10-20)
2. Singapore Civil Defence Force (SCDF) — About Civil Defence Shelter — https://www.scdf.gov.sg/home/civil-defence-shelter/about-civil-defence-shelter (accessed 2026-10-20)
3. Singapore Civil Defence Force (SCDF) — Types of Shelter — https://scdf.gov.sg/home/civil-defence-shelter/types-of-shelter (accessed 2026-10-20)
4. Building and Construction Authority (BCA) — Household and Storey Shelters — https://www1.bca.gov.sg/regulatory-info/building-control/household-and-storey-shelters (accessed 2026-10-20)
5. Attorney-General's Chambers – Singapore Statutes Online — Civil Defence Shelter Act 1997 — https://sso.agc.gov.sg/Act/CDSA1997 (accessed 2026-10-20)