Looking to save some money on your water bill? You might want to change up your shower routine, recent research suggests.

Researchers at the University of Surrey in the UK and others studied the showering habits of German residents. They identified several factors linked to greater water consumption, such as frequently turning off and on the shower. The results indicate that even small tweaks in how we take a shower could lead to meaningful improvements in saving water, the researchers say.

“It turns out the biggest drivers of water use are not who you are or where you live. What matters most is what you actually do in the shower,” said study co-author Pablo Pereira-Doel, a fellow at the Institute for Sustainability at the University of Surrey, in a statement from the university.

How to save some water

Water remains a precious commodity. And in many parts of the world, showers and baths are the single largest contributor to the water bill, accounting for 25% to 40% of indoor water use on average, according to studies cited by the researchers. While there’s been a lot of focus on using policy (price increases) or technology (more efficient showerheads) to reduce shower-related water consumption, the researchers say less attention has been paid to studying people’s actual habits in the shower or tub.

The team analyzed data collected from 319 German households. The bathrooms in these homes were outfitted with smart sensors that could measure when and how people took their showers; volunteers in the study were also asked to fill out surveys immediately after they showered. All told, they studied 8,550 “showering events” during a single winter.

After adjustment, factors like gender, employment, how many people lived in the home, or who was in charge of the water bill seemed to have only marginal or uncertain effects on how long people took showers. And the largest predictors of shower length were actually behavioral.

Specifically, showers where people applied shampoo two or more times were about 27% longer than showers with one application of shampoo. And showers where people turned off the water three or more times were roughly 20% longer than showers with no water pauses at all. Other relevant factors included age (people under 50 tended to shower longer) and whether people lived in places where the water supply was softer or harder (softer-water showers were about 23% longer than harder-water ones).

What this means

The team’s findings, published Thursday in the Journal of Environmental Management, point to reasonable steps we can take to curb excessive water usage, the researchers say, such as encouraging people to cut down on the number of shampoo products they use.

“If we want to reduce household water consumption, we need to design solutions that work with peopleâs habits rather than against them,” said Pereira-Doel. “Behavioral nudges, smarter feedback devices and better product design could all play a role in helping people use less water without sacrificing comfort.”

Meanwhile, I’m just wondering if singing in the shower promotes longer shower times, because if so, that would personally hit me right where it hurts.