Home Assistant automations are rules that make your smart home react automatically to events, schedules, and sensor data. Instead of manually turning lights on and off through an app, automations handle it for you: lights turn on at sunset, the thermostat adjusts when you leave home, and a notification arrives when the washing machine finishes. Once you understand the trigger-condition-action pattern that every automation follows, building your own becomes intuitive.
Every Home Assistant automation consists of three parts. A trigger starts the automation (motion detected, time reached, device state changed). A condition optionally checks whether the automation should proceed (only if it is after sunset, only if someone is home). An action is what the automation does (turn on light, send notification, adjust thermostat). This guide walks through 10 practical automations that cover the most common smart home scenarios.
How to Create an Automation in Home Assistant
Open the Home Assistant dashboard and navigate to Settings, then Automations & Scenes, then Create Automation. Choose Create New Automation to start from scratch, or browse blueprints for pre-built templates. The visual automation editor lets you build automations by clicking through menus rather than writing YAML code, though advanced users can switch to YAML mode for more control.
Give every automation a descriptive name that explains what it does: “Turn on porch light at sunset” is better than “Automation 1.” This becomes important when you have dozens of automations and need to troubleshoot or disable specific ones.
Automation 1: Lights On at Sunset
Trigger: Sun – Sunset (with optional offset of -30 minutes for pre-darkness). Action: Turn on your exterior lights or living room lamp. This is the most common first automation and immediately demonstrates the value of smart home automation. You never need to remember to turn on the porch light again.
Add a second action to turn these lights off at a specific time (11 PM) or at sunrise. You can include both in a single automation using the Wait for trigger or create a separate “Lights off at sunrise” automation.
Automation 2: Motion-Activated Hallway Light
Trigger: Motion sensor state changes to “detected.” Condition: Time is between 10 PM and 7 AM (so it only activates at night). Action: Turn on hallway light at 30 percent brightness, wait 3 minutes, then turn off. Night-mode motion lighting is transformative for hallways, bathrooms, and stairs. The low brightness preserves night vision while providing enough light to navigate safely.
Automation 3: Welcome Home Lights
Trigger: Your phone connects to home WiFi (using the Home Assistant companion app’s device tracker) or a person entity changes to “home.” Condition: Sun is below horizon. Action: Turn on entryway, living room, and kitchen lights. The house lights up as you walk in the door without touching a switch. Combine with a smart lock automation that unlocks the door when your phone is detected nearby for a fully automated arrival experience.
Automation 4: Away Mode – Everything Off
Trigger: All person entities change to “not home” (last person leaves). Action: Turn off all lights, set thermostat to eco mode, arm the security system, and lock all smart locks. This automation ensures nothing is left on when the house is empty. Use the All option in the person trigger to ensure it only fires when the last person leaves, not when one person departs while others remain.
Automation 5: Morning Routine
Trigger: Time is 6:30 AM on weekdays. Condition: Someone is home. Action: Gradually increase bedroom light brightness over 15 minutes (simulating sunrise), set thermostat to comfortable temperature, start coffee machine via smart plug. A morning routine automation replaces the alarm clock with a gentle wake-up experience. The gradual light increase is more pleasant than a sudden alarm and helps regulate your circadian rhythm.
Automation 6: Washing Machine Finished
Trigger: Smart plug energy monitoring drops below 5 watts (indicating the washing machine cycle completed). Action: Send notification to your phone: “Washing machine finished, time to move clothes to dryer.” This uses the energy monitoring capability of smart plugs to detect appliance states without any special sensors. The same technique works for dishwashers, dryers, and any appliance with distinct power consumption patterns.
Automation 7: Temperature-Based Fan Control
Trigger: Temperature sensor reads above 25 degrees Celsius. Condition: Someone is home. Action: Turn on fan via smart plug. Add a second trigger for when temperature drops below 23 degrees to turn the fan off. This creates a simple thermostatic control for any fan using a temperature sensor and smart plug.
Automation 8: Doorbell Notification With Camera Snapshot
Trigger: Doorbell button pressed or doorbell motion detected. Action: Send push notification to all household phones with a camera snapshot attached. If no one answers within 2 minutes, send a second notification. This ensures you never miss a delivery or visitor, even when you are away from home.
Automation 9: Bedtime Routine
Trigger: Time is 11 PM, or manually triggered via a dashboard button. Action: Turn off all lights except bedroom, lock front door, set thermostat to sleep temperature, enable Do Not Disturb on smart speakers. Having this as both a timed and manual automation gives flexibility. On early nights, tap the dashboard button. On nights you stay up late, the 11 PM trigger catches whatever you forgot.
Automation 10: Water Leak Alert
Trigger: Water leak sensor state changes to “wet.” Action: Send critical notification to all household phones, flash smart lights red, play alert on smart speakers. Water leak sensors placed near washing machines, dishwashers, water heaters, and under sinks can prevent thousands of dollars in water damage by alerting you immediately when a leak starts.
Frequently Asked Questions
Do automations work when Home Assistant is offline?
No. Home Assistant automations require the Home Assistant server to be running. If your Raspberry Pi or server loses power, automations stop. This is why many users run Home Assistant on a dedicated device with a UPS (uninterruptible power supply) for reliability.
Can I trigger an automation manually?
Yes. Every automation has a “Run” button in the Automations list. You can also create dashboard buttons that trigger automations, or use Siri/Alexa/Google voice commands to activate specific automations by name.
What is the difference between automations and scenes?
A scene is a saved snapshot of device states (living room light at 50 percent, TV on, thermostat at 22 degrees). An automation is a rule that triggers actions based on events. Automations often activate scenes as their action. Think of scenes as “what” and automations as “when.”
How many automations can Home Assistant handle?
Home Assistant can handle hundreds of automations without performance issues. Users with 200+ automations report no noticeable slowdown. The system evaluates triggers efficiently and only processes the conditions and actions of automations whose triggers actually fire.
