House Construction
Overhead Tank Capacity: A Simple Calculation
An undersized tank means pumps running all day; an oversized one adds structural load and stale water.
The basic formula
Daily demand = people × litres per person per day. For Bengaluru homes we plan for 135 litres per person.
Example
A family of 5 → 5 × 135 = 675 litres/day. Add about 50% buffer and you arrive at a 1,000-litre overhead tank, with a sump of 1.5–2 days’ demand.
Planning tips
- Place the tank over a column or beam, never mid-slab.
- Provide a separate tank for rainwater or recycled water if you plan to reuse it.
- Allow for maintenance access and an overflow pipe.
