Building Code Requirements in Delhi

Delhi builds to its own Unified Building Bye-Laws 2016 (UBBL-2016), notified by the Delhi Development Authority and incorporating NBC 2016. Where NBC sets one flat national figure, UBBL sometimes grades it by the size of the dwelling unit instead.

Habitable-room area is graded by unit size. NBC 2016 sets one flat national rule — 9.5 m² for a single-room dwelling, or 9.5 m² plus a 7.5 m² second room. UBBL’s Table 7.1 (§7.1.3) grades that instead:

That’s a genuinely more permissive rule for smaller Delhi flats than NBC’s single national figure allows.

Low-rise staircase width is graded the same way. NBC’s residential stair-width default is a flat 1.00 m. UBBL’s Table 7.1 (item 12) grades a low-rise staircase by the same dwelling-unit-size bands: 0.9 m for units up to 50 m², 1.0 m for units above 50 m² — narrower than the national default for the smaller-unit band.

Get the basics right and check the current UBBL text for anything not covered here — our stair calculator and concrete calculations guide handle the day-to-day maths either way.

Related

• India’s building code hub — how NBC 2016 and state bye-law adoption work together.
• Indian stair rules — the NBC 2016 national figures this page’s deltas sit against.
• Indian room height & area rules — the national 9.5/7.5 m² rule UBBL’s grading replaces.

Read this first. Delhi’s Unified Building Bye-Laws (UBBL) 2016 still names and incorporates NBC 2016 specifically, so it remains the practical, enforced reference for Delhi today — even though BIS has withdrawn NBC 2016 nationally and replaced it with SP 7:2026 (“National Building Construction Standards 2026”), gazette-notified in 2026 (reported 30 April 2026). That’s a change to the national standard only; it doesn’t take effect here until UBBL itself is updated to reference it. Confirm which edition your current UBBL/NBC reference actually adopts before you rely on any figure above.