What determines the cost of a sauna or hot tub for your guests
A sauna or hot tub is one of the finest features of a stay for guests, and often the biggest power consumer in your home as a host. The costs such a device incurs come down to three simple things: how much power the device draws, how long it runs, and what you or your energy supplier charge per kilowatt hour. Multiply those three and you'll know roughly what a session costs.
An electric sauna typically draws between four and nine kilowatts, depending on the size of the cabin and the type of heating element. A hot tub uses electricity mainly for heating the water and, to a lesser extent, for the pump that circulates the water; together that usually comes to somewhere between one and three kilowatts, with a distinct peak when the water heats from cold to warm. Air conditioning sits well below that at an average of one to two kilowatts, though this varies considerably per model and outdoor temperature.
A concrete example: a six-kilowatt sauna running for two hours consumes twelve kilowatt hours. If you charge thirty-five cents per kilowatt hour, that one session costs roughly four euros and twenty cents in electricity alone for heating; if the sauna then glows on low power for another hour, you add that on top.
Why this amount differs per property
The final amount depends not only on the device itself, but also on how your guests use it. Some guests run the sauna for an hour and neatly switch it off afterwards; others use the hot tub every evening for half an hour. The season also matters: in winter, an outdoor hot tub heats more slowly because the surrounding water cools faster, which increases consumption. If you want to know how that works out per season and per device in your own property, you'll find in the knowledge base with explanations per device and season concrete guidelines to work that out yourself.
As a host, the question is really not just what the device costs, but also how you recover that amount. If you charge a fixed amount per stay, you risk that a thrifty guest pays too much and an intensive user pays too little. If you charge per kilowatt hour, each guest pays exactly what they consume, including the sauna or hot tub. Which approach fits your situation depends on how many properties you rent and how predictable the usage is; a few questions show you which billing method suits you.
What this means for your own rate
Separately metering a sauna or hot tub is usually not necessary: it's about the total consumption of the property, from coffee maker to sauna, which is tracked via one module in the meter cabinet and charged back to the guest. The hardware and subscription per property cost a fixed amount per month, with a small surcharge on each kilowatt hour sold added on top; an overview of these amounts is on the page with current prices.
For the installer: power and time calculated
The math behind the example above is simple: kilowatt hours equal power in kilowatts multiplied by time in hours. A 6 kW sauna running for 120 minutes (2 hours) comes to 6 × 2 = 12 kWh. With a hot tub, the heating peak also counts: when first filled or after a longer period off, the heating often draws full power for several hours, after which the thermostat switches to brief, lower pulses to maintain temperature. If you want to see exactly how that measurement technically comes about, then the page on how the measurement works explains which data are recorded and why.
Passing costs on to guests: what is and isn't allowed
Whether and how you may pass on these costs to guests depends on the country in which you operate and your own rental terms. Staywatt is a metering and payment system and does not make any statement about what is permitted in your specific situation; for that question we refer you to a legal advisor or to the competent supervisory authority in your country.
Do you want to know what a sauna, jacuzzi or air conditioning costs on average in your own property, and which billing method suits it? Do the free quick-scan or browse through the knowledge base; within half an hour you'll know where you stand.