National Building Code of India and IS Roofing Standards

The National Building Code of India (NBC) is a national instrument giving guidelines for regulating building construction across India. It is published by the Bureau of Indian Standards (BIS), the national standards body. The code was first published in 1970 and has since been revised, with the current edition being NBC 2016.

The NBC is a model document. Local authorities, development authorities and states incorporate it into their building bye-laws, sometimes with changes, so the rules in force can differ from city to city.

Structure of NBC 2016

NBC 2016 is organized into Parts 0 to 12 across two volumes:

• Volume 1 – Part 0 Integrated Approach; Part 1 Definitions; Part 2 Administration; Part 3 Development Control Rules; Part 4 Fire and Life Safety; Part 5 Building Materials; Part 6 Structural Design.
• Volume 2 – Part 7 Construction Management; Part 8 Building Services; Part 9 Plumbing Services; Part 10 Landscape, Signs and Outdoor Display Structures; Part 11 Approach to Sustainability; Part 12 Asset and Facility Management.

Roofing in the NBC

Roofing is not a single chapter. Relevant provisions are spread across:

• Part 4 – fire safety, including combustibility of roof coverings
• Part 5 – building materials, which references Indian Standards (IS) for roofing products
• Part 6 – structural design, including loads such as wind on roofs and cladding
• Part 9 – plumbing, including rainwater drainage from roofs
• Part 11 – sustainability, covering topics such as rainwater harvesting and reflective roofs

IS standards

BIS publishes Indian Standards (IS) for roofing materials such as coated steel sheet, clay and concrete tiles, fibre-cement sheets and waterproofing systems. Some products must carry the BIS (ISI) certification mark by government order, while certification is voluntary for most others. Steel products are among the categories where certification is mandatory.

Background on BIS

BIS's predecessor, the Indian Standards Institution, was set up by a resolution in 1946. BIS was established as a statutory body in 1986, and the Bureau of Indian Standards Act, 2016, which replaced the 1986 Act, came into force on 12 October 2017.

Practice

Flat reinforced concrete roofs with waterproofing and surface treatments are common in Indian cities, while metal sheet and tile roofs are widespread in industrial, rural and coastal buildings. The NBC and IS standards apply across all of these, but enforcement depends on local building authorities.