E: 06/10 Planter for your garden or outside space (United Utilities customers)

libra10

United Utilities

How many litres of rain comes off the roof of an average terraced house in a year?

I think the answer is 30,000, but unsure.

T&C
https://www.unitedutilities.com/win-a-fantastic-planter/water-butt-terms-and-conditions/

https://www.unitedutilities.com/win-a-fantastic-planter/

RoCoB

Let's say for example that you are three persons living in a two-bedroom terraced house in Birmingham with a 55 square metre roof area (the average for two-bed terrace houses). As one cubic metre is 1,000 litres, you can expect to harvest 37,455 litres of rainwater per year.

libra10

Using Google search, I also found the following -

A surprisingly small roof area will give a lot of rainwater: a typical terraced house with a 6 by 8 metres roof area could give 30,000 litres a year depending on the area of the country you live in.