Water flows from a bathroom shower head.
Water flows from a bathroom shower head. - 

Jeremy Hobson: So have you taken a shower yet this morning? Well if you have and it lasted less than eight minutes, your shower was shorter than average. That's according to new research from the consumer products company Unilever.

The BBC's Matt Davies reports.

Matt Davies: The researchers spied on 2600 showers taken by 100 families. And they found that the average shower uses less water than taking bath -- about 4 gallons less. But people spent more time in the shower than expected. And means they used more hot water -- and more energy to heat the water. An eight minute shower costs a household $648 a year.

Paula Owen is an independent environmental advisor.

Paula Owen: We recommend that people spend about 4 minutes in the shower. And that if you shower for that amount of time it's much better for the environment, for your heating bills and for your water bills.

Researchers say they were surprised at how long people spent in the shower and that's because early data was collected by simply asking bathers questions -- whereas Unilever's new information was collected by putting electronic devices in the shower. And that provided more accurate results, no matter how creepy you think that is.

In London, I'm the BBC's Matt Davies for Marketplace.