What is the minimum daily water requirement for a typical residential flat?

It ranges from 135 lpcd (litres per capita per day) for LIG to 200 lpcd for HIG, including flushing requirements (Table 1).

How much water should be stored in a domestic overhead tank?

At least one-third (1/3) of the building's total daily water requirement (Clause 7.1.1).

What is the minimum pressure that must be available at the highest tap in a building?

A minimum head of 0.05 N/mm² (approximately 5 metres) should be available at the highest fixture (Clause 8.2.3).

What is the hydraulic test pressure for new water supply pipes?

The system should be tested at 1.5 times the maximum working pressure or 1.0 N/mm² (approx. 10 bar or 100m head), whichever is greater, for a period of at least one hour (Clause 11.1.1).

IS 12183

: 2000

Code of practice for plumbing in multi-storied buildings, Part 1: Water supply

CurrentFrequently UsedCode of PracticeBIMMEP · Public Health Engineering

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This code provides guidelines for the design and installation of water supply systems in multi-storied buildings. It covers material selection, system types (direct and indirect), water demand calculation, storage tank sizing, pipe sizing, and testing procedures. It is the fundamental document for plumbing water supply design in high-rise structures in India.

Code of practice for plumbing in multi-storied buildings, Part 1: Water supply

Quick Reference Values

Minimum water supply for LIG residences135 litres per capita per day

Minimum water supply for HIG residences200 litres per capita per day

Minimum residual head at ferrule (direct supply)22 m

Minimum water pressure at highest fixture0.05 N/mm² (approx. 5 m head)

Minimum domestic water storage capacity1/3 of the total daily water requirement

Minimum fire fighting water storage (if no other source)Varies by building type, e.g., 100,000 litres for Residential building >15m height

Hydraulic test pressure for pipework1.5 x max working pressure or 1.0 N/mm², whichever is greater

Practical Notes

The code strongly advocates for an indirect supply system (via overhead tanks fed by booster pumps) for most multi-storied buildings to ensure adequate and consistent pressure at all floors.

The 'loading unit' method (Tables 3 & 4) is crucial for accurately estimating the peak flow rate (probable simultaneous demand), preventing oversizing or undersizing of pipes.

When designing, always separate the domestic water supply lines from the fire-fighting lines, even when they originate from the same tank, using non-return valves to prevent water being drawn from the fire reserve.