Saving on hot water: using less gas, electricity and water
By Laurens Arends · updated 05-10-2026
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Saving on hot water usually starts in the shower
If you want to save hot water, you don't need to buy a new installation straight away. The length of your shower and the amount of water the shower head lets through together determine how much water you heat. The CBS study Watergebruik Thuis is the most recent detailed national measurement. In it, a shower lasted 7,4 minutes on average and 56,9 litres were used per shower. Per person that was 46,2 litres a day. The daily figure is lower because Dutch people showered on average 0,82 times a day.
| Way to save hot water | Indicative saving per year | Effort |
|---|---|---|
| Shortening showers from 7,4 to 5 minutes, two people | € 79 plus the water costs saved | Low |
| Water-saving shower head, two people | Approximately € 55 | Low |
| Thermostatic shower mixer tap | Approximately € 5 | Medium |
| Replacing one bath a week with a 5-minute shower | Approximately € 38 | Low |
| Using 5 litres less hot tap water every day | Approximately € 15 | Low |
| Central heating boiler from comfort mode to eco mode | About € 23 | Low |
| Shower heat recovery unit with four showers a day | € 91 to € 142 gross; approximately € 21 to € 115 after depreciation | Medium to high |
Sources: Milieu Centraal, Saving in the shower, Milieu Centraal, Central heating boiler on eco mode, Milieu Centraal, Shower heat recovery en Vewin, drinking water rates 2026. The amounts are our own calculations using € 1,52 per m³ of gas and the weighted Dutch drinking water rate of € 2,71 per m³ including taxes. The outcome may differ due to your showering habits, water pressure and contract rate. Price level: 2026.
Shower for less time and measure your shower head
Showering for 5 instead of 7,4 minutes cuts almost a third of the shower time. For this, Milieu Centraal calculates with about € 36 per person a year at a gas price of € 1,37. We work with 2026 price levels and therefore an indicative gas price of € 1,52. As a result, the saving rises to about € 40 per person. With two people showering daily, the saving comes to approximately € 79 a year. The water saving comes on top of that.
Preferably use a water-saving shower head that lets through a maximum of 7,2 litres per minute. Don't know how much water your shower head lets through? Then let the water reach temperature, then catch exactly one minute of water in a bucket with a measuring scale and read off the number of litres. Replace the shower head if it lets through more water. A water-saving shower head uses about 20% less water and energy than a standard shower head. If you replace a rain shower, Milieu Centraal mentions a saving of up to 40%.
A shower is usually more economical than a bath
According to Milieu Centraal, an average bath holds about 140 litres of water. That is almost four times as much water and energy as a five-minute shower. The CBS arrived at an average of 142,4 litres per bath in its national measurement, virtually the same result.
So a short shower is much more economical than a bath, even if several people use the same bath water. That does not automatically apply to a long shower with a rain shower head: CBS measured an average of 72,5 litres per shower with a rain shower and 79,6 litres with a massage shower. The minutes and the litres per minute both count.
Don't let hot water run away for nothing
For rinsing, washing hands and a lot of cleaning, cold water is sufficient. Turn the tap off while lathering up and collect the dishes rather than running hot water again for every plate. If the hot water supply is far from the kitchen, cooled-down water from the pipe flows out first. During a renovation, a shorter pipe route can limit that waiting loss. Be careful, though, because an electric kitchen boiler is not always better. Such an appliance can reduce water loss, but adds standby loss and electricity consumption.
Set the central heating boiler to eco mode, but keep tap water safe
In comfort mode, a combi boiler keeps itself warm so that hot water comes out of the tap faster. In eco mode, the boiler only starts heating when you ask for hot water. According to Milieu Centraal, eco mode saves gas, although you sometimes wait a little longer. So you use more water, but save expensive gas.
Do not keep lowering the temperature of the tap water to save energy. The RIVM advises setting a boiler or combi boiler to at least 60 °C to limit legionella growth. The temperature of the central heating water for the radiators can be lowered further, though.
Shower heat recovery: recovering heat from draining shower water
A shower heat recovery unit transfers heat from the waste water to the cold incoming water. The two water flows remain separate. According to Milieu Centraal, this saves you 40 to 50% of the energy for showering. The model gives 45 to 70 m³ of gas a year for three people.
For a family with four showers a day, we calculate 45 to 70 × 4 ÷ 3 = 60 to 93 m³. At € 1,52 per m³ that is € 91 to € 142 a year. The vertical shower pipe heat recovery unit performs best, but requires a thorough renovation. With thorough renovations, always check whether you are eligible for subsidies.
Which shower heat recovery unit suits your bathroom?
A vertical shower pipe heat recovery unit makes the best use of the temperature difference and delivers the highest gas saving in the Milieu Centraal model. You do need sufficient vertical drain pipe and access under or next to the shower for it. A heat exchanger in a shower drain or shower tray is easier to fit in when the bathroom is being opened up anyway.
| Type of shower heat recovery unit | Investment | Gross saving | Depreciation over 30 years | Net after depreciation | Simple payback period |
|---|---|---|---|---|---|
| Standalone shower heat recovery unit | € 700 | € 91 per year | € 23 a year | € 68 a year | 7,7 years |
| Shower tray heat recovery unit | € 2.000 | € 111 a year | € 67 a year | € 44 a year | 18,0 years |
| Shower drain heat recovery unit | € 2.700 | € 111 a year | € 90 a year | € 21 a year | 24,3 years |
| Vertical shower pipe heat recovery unit | € 800 | € 142 a year | € 27 a year | € 115 a year | 5,6 years |
Source: Milieu Centraal, costs, lifespan and saving of shower heat recovery, last modified on 30 June 2026. The stated investment applies, according to Verbeterjehuis.nl to installation during a bathroom renovation and includes fitting. We scale the gas saving from three to four showers a day and calculate with € 1,52 per m³. The depreciation is the investment divided by 30 years, without residual value, interest, maintenance or subsidy. The net annual saving is the gross energy saving minus this depreciation.
You see the gross saving back on the energy bill every year. The net saving after depreciation is an economic comparison: in reality you pay part of the saving up front. At constant prices (2026 price level), a vertical shower pipe heat recovery unit indicatively yields 30 × € 142 − € 800 = € 3.460 over 30 years. For a shower drain heat recovery unit, that is 30 × € 111 − € 2.700 = € 630. If the bathroom has to be opened up solely for the heat recovery unit, there are additional building costs.
A shower heat recovery unit saves heat, not drinking water. The system only works while warm shower water drains away as new water is supplied. That is why the same heat exchanger is of little use for a bath: when filling it, no warm water is draining away yet. The saving is therefore greater if you take a bath less often and shower more often.
Do you get ISDE for a shower heat recovery unit?
In 2026, a shower heat recovery unit is not among the ISDE measures eligible for subsidy for homeowners. The new ventilation subsidy of € 400 applies, according to the RVO only to CO₂-controlled extraction and balanced ventilation that recovers heat from extracted air. That is something different from recovering heat from shower water. However, if you combine the bathroom renovation with insulation, a heat pump or a solar water heater, you may well qualify for a subsidy. In that case, check the current ISDE options before you place the order.
Frequently asked questions about saving hot water
How much gas do you use for hot water?
According to Milieu Centraal, in a gas-heated household almost 25% of gas consumption goes to hot water for the bathroom and kitchen. The actual share depends on your showering habits and the home. In a well-insulated house, gas use for space heating falls, so hot water can make up a larger part of total gas consumption.
How much do you save by showering for five minutes?
Milieu Centraal calculates that a reduction from 7,4 to 5 minutes saves about € 36 per person a year at a gas price of € 1,37. Converted to € 1,52 per m³ at 2026 price levels, that is about € 40 per person or € 79 for two people. The additional saving on drinking water is not included in that amount.
How much do you save with a water-saving shower head?
According to Milieu Centraal, a water-saving shower head uses about 20% less water and energy than a standard shower head. The shower head may let through a maximum of 7,2 litres per minute. Compared with a rain shower, the reduction can rise to 40% according to the same source, but your outcome depends on the current flow rate and shower duration.
Is a shower heat recovery unit cost-effective?
That mainly depends on the number of showers and the type of heat exchanger. For four showers a day, the gross gas saving comes to about € 91 to € 142 a year. After depreciating the investment over 30 years, an indicative € 21 a year remains for a shower drain heat recovery unit, up to € 115 for a vertical shower pipe heat recovery unit. This calculation assumes that the heat recovery unit is fitted during a planned bathroom renovation. Renovating a bathroom solely for a (vertical) shower heat recovery unit is in principle not cost-effective.
May I lower the temperature of my boiler?
Not indefinitely. The RIVM advises setting a boiler or combi boiler to at least 60 °C to limit the growth of legionella. This concerns the minimum tap water temperature, not the flow temperature of the central heating water for radiators or underfloor heating.
Is a shower heat recovery unit the same as a ventilation heat recovery unit?
No. A shower heat recovery unit extracts heat from draining shower water and uses it to preheat cold tap water. A ventilation heat recovery unit extracts heat from extracted indoor air and transfers it to fresh ventilation air.