This article describes specific automation scenarios that have been configured and tested in Czech apartments. Each scenario includes the hardware used, approximate cost in CZK at Czech retail prices, and an honest assessment of the outcome — including limitations specific to Czech building types and utility infrastructure.
The examples are built on Home Assistant as the central automation engine, running on a Raspberry Pi 4 (4 GB RAM). The Zigbee devices communicate through a Sonoff Zigbee 3.0 USB Dongle Plus via Zigbee2MQTT. The Netatmo thermostat uses its cloud API, accessed through the official Home Assistant Netatmo integration.
Scenario 1: Heating Schedule with Occupancy Override
Context
Czech district heating (dálkové vytápění) does not allow precise temperature control at the radiator level in older buildings — the building regulates hot water supply to the whole block. In buildings with individual gas boilers or heat pumps, precise per-room temperature control is achievable. The Netatmo Smart Thermostat (approximately 3,800 CZK at Alza.cz) integrates with Home Assistant and supports schedule-based control with manual override.
Setup
The automation runs a weekday heating schedule: 20°C from 06:30 to 08:00 (morning routine), drops to 18°C from 08:00 to 16:30 (working hours), returns to 21°C from 16:30 to 22:30 (evening), then reduces to 17°C overnight.
The occupancy override uses a Zigbee presence sensor (Aqara FP2, ~1,890 CZK) placed in the living room. If the sensor detects no presence for 45 minutes during a period that would normally be heated, the automation reduces the setpoint to 18°C. When presence resumes, heating returns to the scheduled temperature within 15 minutes.
Measured result: Over the 2025/2026 heating season (October–March), the occupancy-based override reduced gas consumption by approximately 14% compared to the fixed schedule alone, based on meter readings. The flat is a 65 m² Praha 4 apartment with a Baxi boiler.
Limitations
Netatmo uses a cloud relay for all commands, even local ones. If the Netatmo cloud is unavailable (rare but documented in the Netatmo community forums), temperature setpoints cannot be changed through Home Assistant until connectivity restores. The thermostat falls back to its last schedule in that case.
Scenario 2: Adaptive Morning Lighting
The Problem with Fixed Scenes
Standard smart lighting scenes set a fixed colour temperature and brightness. In Central European winters, when sunrise in Prague occurs after 07:30, waking at 06:00 in complete darkness with a scene set to "daylight" (6500K, 100% brightness) produces an abrupt and unpleasant start. A circadian-aware approach changes both colour temperature and brightness according to solar data.
Hardware
Two LIFX bulbs (approximately 1,200 CZK each at Mironet) in the bedroom, controlled through the LIFX integration in Home Assistant. LIFX bulbs support the full colour temperature range (1500K–9000K) and use Wi-Fi rather than Zigbee.
Automation Logic
Home Assistant calculates sunrise time daily using the configured GPS coordinates for the flat. The morning lighting automation starts 60 minutes before the occupant's wake-up time (set as an input_datetime helper). Over 30 minutes, brightness ramps from 5% at 2700K to 60% at 4000K. At the wake-up time, brightness reaches 80% at 5000K.
The automation also checks a "sleep mode" boolean. If the occupant set sleep mode the previous evening, the ramp starts 30 minutes later, allowing extra sleep on non-workdays without reprogramming.
Note on Wi-Fi bulbs: LIFX devices require an active Wi-Fi network. During Czech ISP maintenance windows — T-Mobile and O2 both perform scheduled maintenance between 02:00 and 04:00 — if the router reboots, bulbs will drop off the network until it restores. A scheduled restart of the router before midnight eliminates this issue in practice.
Scenario 3: Presence-Based Security Lighting
The Czech Context
Czech law (Act No. 89/2012 Coll., Civil Code, §2900) does not prohibit automated lighting or camera systems in private spaces, but recording of shared building spaces (corridors, entrance halls) is restricted. Presence simulation using interior lighting is entirely legal and requires no notification to neighbours or the building administration.
Setup
When the flat is in "away" mode — triggered either manually or automatically when both residents' phones leave the home Wi-Fi network — an automation runs a randomised lighting simulation:
- Between 18:00 and 23:00, one of three light groups (living room, kitchen, study) activates at a random time within each 45-minute window.
- Brightness varies between 30% and 75%.
- Colour temperature shifts gradually between 2900K and 3400K over 20 minutes before the group switches off.
The randomisation uses Home Assistant's random integration. No two evenings produce the same lighting pattern.
Hardware: IKEA TRÅDFRI Zigbee bulbs (approximately 250–350 CZK each from IKEA.com/cz or Alza.cz), paired directly to the Sonoff Zigbee coordinator via Zigbee2MQTT. No IKEA gateway required.
Total cost of this scenario: Approximately 2,400 CZK for six IKEA TRÅDFRI bulbs and one Sonoff Zigbee dongle (590 CZK). The Raspberry Pi 4 hardware cost is shared across all automations.
Scenario 4: Energy Monitoring and Peak-Hour Avoidance
Czech Electricity Tariffs
Czech electricity distribution uses a two-tariff system (D01d/D02d for households) administered by ČEZ, E.ON, and PRE. The high tariff (VT) applies during peak hours defined by the distributor, typically 07:00–22:00 in the D01d tariff. Off-peak (NT) pricing is significantly lower — approximately 40–45% of the VT rate — making it financially sensible to shift washing machine and dishwasher cycles to the NT window.
Automation
A Shelly Plus 1PM (approximately 690 CZK) is installed behind the washing machine socket. The device exposes a power monitoring API and can be switched remotely. A Home Assistant automation queues a washing cycle: when the occupant presses a physical button (Zigbee IKEA TRÅDFRI shortcut button), the automation checks the current time. If it is within VT hours, it schedules the start for 22:05. If NT hours are already active, it starts immediately.
The automation sends a push notification to the occupants' phones via the Home Assistant companion app, confirming whether the cycle started immediately or was scheduled.
Over 12 months in a two-person household running approximately 6 washing cycles per week, shifting to NT hours reduces washing-related electricity costs by roughly 380–420 CZK/year based on a VT price of 6.5 CZK/kWh and NT price of 3.8 CZK/kWh.
Scenario 5: Ventilation Control by CO₂ Level
Indoor Air Quality in Czech Apartments
Czech building standards (ČSN EN 15665) specify minimum ventilation rates for apartments, but older panel buildings often have passive ventilation only through window gaps and bathroom extraction vents. CO₂ levels in bedrooms during sleep consistently exceed 1,200 ppm in sealed windows conditions, which affects sleep quality measurably according to studies published by the National Institute of Building Sciences.
Setup
An Aranet4 CO₂ sensor (approximately 3,200 CZK, available at Alza.cz) connects to Home Assistant via Bluetooth. The sensor reports CO₂ in ppm every 1–2 minutes. A Shelly Plus 1 (480 CZK) controls an existing bathroom extraction fan via the light switch circuit.
The automation activates the fan when CO₂ in the connected room exceeds 900 ppm and deactivates it when the level drops below 750 ppm. The fan runs silently and does not disturb sleep. During the first winter with this setup, overnight CO₂ levels remained below 900 ppm in 87% of measured nights.
Summary: Hardware and Estimated Costs
| Scenario | Key hardware | Approx. cost (CZK) |
|---|---|---|
| Heating schedule + presence | Netatmo thermostat, Aqara FP2 | 5,700 |
| Adaptive morning lighting | 2× LIFX bulb | 2,400 |
| Presence simulation | 6× IKEA TRÅDFRI, Sonoff dongle | 2,400 |
| Peak-hour energy shifting | Shelly Plus 1PM | 690 |
| CO₂-based ventilation | Aranet4, Shelly Plus 1 | 3,680 |
| Shared infrastructure | Raspberry Pi 4 4GB, SD card, case | ~2,400 |
Prices as of April 2026. Retailer comparison available at Heureka.cz.