Planning and design
Smart bathroom: sensors, thermostats, and what to prepare during construction
A smart bathroom is not just about a mobile app, but about things that turn on and set themselves: sensor mixer, fan with hygrostat, fog-free LED mirror, underfloor heating with a timer, or shower toilet. Most of them require electricity in the right places – so it needs to be planned before tiling.
Many associate the word "smart" with control from a mobile phone. However, in the bathroom, simple automatic functions are most helpful: a fan that turns on by itself when it's humid, a mixer that only flows when hands are under the spout, or a floor that is warm in the morning without you having to think about it. Most of these can be prepared during renovation with just a few hours of the electrician's work – doing it later is usually much harder.
Overview: what a smart bathroom can do
| Function | What they do | What to prepare during construction |
|---|---|---|
| fan with hygrostat | turns on at high humidity, turns off after ventilation | electricity supply, pipe to the shaft or outside |
| sensor mixer | water flows only while hands are under the spout | battery power or electricity supply under the sink depending on the model |
| LED mirror | light at face level, heating to prevent fogging, touch switch | electricity outlet behind the mirror |
| underfloor heating with thermostat | warm floor according to a timer | temperature sensor in the floor, supply to the thermostat |
| heated towel rail with timer | heats towels and the bathroom for a set time | electricity outlet near the radiator |
| light with motion sensor | night light that does not dazzle | box for the sensor or light with a sensor |
| shower toilet | washing with water, drying, heated seat | electricity and water supply at the toilet module |
| thermostatic mixer | maintains the set temperature, safety lock at 38 °C | no electricity, just the right connections |
A fan that thinks for you
A fan with a hygrometer is the most useful 'smart' thing in the bathroom. It turns on automatically when humidity rises after a shower and turns off when it drops. The fan runs for a set time after the light is turned off. The selection is described in the article Bathroom Fan, the performance is calculated by the fan performance calculator.
Taps: sensor and thermostat
Sensor tap is hygienic and saves water – more in the article Sensor Tap. Thermostatic mixer does not require electricity, but does exactly what you expect from a smart bathroom: set the temperature once and it maintains it even when someone else turns on the water. The safety lock at 38 °C protects children and seniors from scalding. How to save more is described in the article How to Save Water in the Bathroom.
Heat according to the programme
Underfloor heating with a programmable thermostat warms the floor in the morning before your alarm and in the evening before bathing, while tempering during the day. An electric heated towel rail with a timer dries towels and warms the bathroom. The floor temperature sensor is installed in the floor before the floor tiles – it cannot be added later. More in the article Underfloor Heating in the Bathroom.
Light and mirror
An LED mirror with light and anti-fog heating is practical right after a shower. The light with a motion sensor or a dim night light near the floor is appreciated by children and older people – it won't dazzle at night. The colour of the light, height, and coverage of the fixtures are described in the article Bathroom Lighting, and the selection of mirrors is covered in the article Mirror for the Bathroom.
Shower toilet: preparation in the module
A shower toilet requires an electricity and water supply at the bowl. Some concealed cistern frames already account for this – for example, Geberit Duofix has a pipe sleeve for the supply line to the shower toilet and a box for the electrical supply through an opening with a diameter of 68 mm. Alcadrain modules have provisions for connecting a holder with a G1/2" transition for bidet seats and sprays. If you are not buying a shower toilet yet, leave the supplies prepared – it won't require demolition later. More in the articles Shower Toilet and Concealed Cistern Frame.
Electricity and safety
The more electrical devices, the more important it is to adhere to zones. Lights and appliances in zones 1 and 2 must have a rating of at least IPX4, sockets and switches must be outside zones 0, 1, and 2, and all circuits in the bathroom are protected by an RCD. The number of outlets, circuits, and their protection is designed by an electrician. Details in the article Electricity and Zones in the Bathroom.
Control from your mobile and smart home
The thermostat for underfloor heating, lights, and fan can be connected to a smart home system and controlled from your mobile. This makes sense if you already have such a system in your house. Keep in mind that there must be a good Wi-Fi signal in the bathroom and every function must also be controllable without a mobile – by a switch or button.
What is worth it and what to consider
- It is almost always worth it: fan with hygrometer, thermostatic mixer, LED mirror with heating, programmable thermostat for underfloor heating, electrical preparation at the toilet.
- As needed: sensor tap, light with a sensor, shower toilet, radiator with a timer.
- Consider: items that require an app for every use, and devices without available spare parts.
Sensor taps, LED mirrors, and thermostatic mixers can be viewed live at the store in Senec at Bratislavská 71. On the e-shop vkupelni.sk you will find sensor taps, LED mirrors, and thermostats. Electricity and installations should always be designed and done by a professional – electrician and plumber.
Checklist for the electrician
- outlet behind the mirror for the LED mirror and a separate switch for the light by the mirror,
- supply and switch or hygrometer for the fan,
- supply to the underfloor heating thermostat and sleeve for the temperature sensor in the floor,
- outlet by the heated towel rail,
- electricity supply at the toilet module for the shower toilet or touchless flushing,
- supply under the sink for the sensor tap, if it is not battery-operated,
- sockets outside zones 0, 1, and 2, RCD, and circuits according to the electrician's design.
Sources: Geberit – catalog sheet Duofix with Sigma 12 cm (sleeve for shower toilet, box for the wall for opening ø 68 mm), Alcadrain – technical sheet Sádromodul (preparation for connection G1/2" for bidet seats and sprays), our articles Electricity and Zones (IPX4, sockets outside zones), Shower Mixer (safety lock 38 °C) and Bathroom Fan (November 2026).
Terms in the glossary: Hygrometer · Underfloor Heating · Heated Towel Rail · Shower Toilet · Thermostatic Mixer · Fan Run-On
Frequently Asked Questions
What is a smart bathroom?
A bathroom with functions that turn on and set themselves – fan with hygrostat, sensor mixer, LED mirror with heating, underfloor heating with a timer program, or shower toilet.
What to prepare during renovation?
Electrical outlets behind the mirror, near the fan, radiator, thermostat, and WC module, temperature sensor in the floor, and water supply for the shower toilet. They are designed by an electrician and plumber.
Is a sensor mixer worth it?
It is hygienic and saves water as it only flows when hands are present. Depending on the model, it requires batteries or an electrical supply under the sink.
How to prepare the WC for a shower toilet?
For the bowl, an electrical and water supply is needed. Some modules have preparation – for example, Geberit Duofix has a conduit for water supply and a box for electricity, Alcadrain has preparation for G1/2" connection.
What rating must lights have in the bathroom?
In zones 1 and 2, at least IPX4. Sockets and switches should be outside zones 0, 1, and 2, and the circuits are protected by an RCD.
Can the bathroom be controlled from a mobile phone?
Yes, the thermostat, lights, and fan can be connected to a smart home system. However, each function must also be controllable via a switch.
Does the thermostatic mixer need electricity?
No, the thermostatic mixer operates mechanically. It maintains the set temperature and a safety feature at 38 °C protects against scalding.
What is a fan with a hygrostat?
A fan with a humidity sensor that turns on automatically when humidity rises after a shower and turns off after ventilation.
Is a heated LED mirror worth it?
Yes, if you want to shave or apply makeup right after a shower. The heating prevents fogging, and the light is positioned directly in front of your face. An electrical outlet needs to be prepared behind the mirror.
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