Heating domestic water makes one fifth of the total energy consumption in a Finnish home. War water consumption varies significantly between families and family members, and the difference in the use of water between similar apartments may be up to tenfold.

Showers consume warm water and energy in particular.

The energy used for 12 minutes in the shower allows the use of refrigerator-freezer for 6 days or a television for more than 4 days non stop.

Means to reduce the carbon footprint of warm water:

• Water saving heads for jet mixers and kitchen faucets and flow nozzles reduce water consumption up to 50% compared to when they were not in use.
• In detached houses, adjusting the constant pressure valve is a way to reduce water consumption significantly: 3–4 bar is enough or less in one-storey buildings.
• Apartment-specific water meters, water-saving fittings and correctly adjusted pipeline network reduce water consumption in semi-detached and apartment houses by 10–30%.
• Solar collectors can produce half of the warm water needed at home during one year.

The most effective way to save warm water is to change one’s ways of living: take quick showers and avoid running water unnecessarily. Use of a timer may help estimate the time spent in the shower. Two minutes is long enough; the water does not need to run during shampooing, for example.