: Many university libraries provide students with digital access to the full BIS catalogue.

Official public repositories, such as Public.Resource.Org and the , frequently host the core "legally binding" versions of IS 3646 (Part 1, 2, and 3) for free download. However, Part 5 specifically for hospitals is often harder to find as a standalone free PDF.

: Peer-shared versions of Part 2 (which includes hospital data) can be viewed on sites like Scribd or Archive.org.

If you are looking for hospital lighting standards, they are frequently covered under:

: Calculation of coefficients of utilization (BZ method).

: Modern lighting requirements for healthcare facilities are often cross-referenced with the NBC, which incorporates these older IS codes into its latest revisions. Recommended Lux Levels for Hospitals