5 powerful smart home automations you can build without buying any new devices

Published Oct 21, 2026, 11:00 AM EDT Adam has a degree in Engineering and has a life-long interest in technology. He has been writing for over a decade for various print and online publications, with a focus on consumer tech. He joined How-To Geek in 2024 while working at Pocket-lint. As well as being a long-term fan of Apple products, he also has a strong interest in smart home tech, running a Home Assistant server at home to automate all his smart home devices. He believes that the ideal smart home should work with minimal interaction from the user, with automations running as if by magic rather than requiring you to push buttons on a control panel. You can find more of his work on Muck Rack. Setting up a smart home can be an expensive business. Not only do you need a device to run your smart home, but you also need all the devices for it to control. If you already have smart home devices set up, however, then there are plenty of incredibly useful automations that you can set up without needing to buy anything new. Make your smart bulbs mimic the sun Adaptive lighting can be really impressive Adaptive lighting is one of the simplest ways to give your smart home a real wow factor with nothing more than the smart bulbs you already own. Even if you're using relatively cheap bulbs, it can make your smart home feel expensive. Adaptive lighting automatically adjusts the brightness and color temperature of your smart bulb over the course of the day to mimic natural sunlight. In the morning, your bulbs can start off fairly dim and warm, just like the light that you get after sunrise, and as the day progresses, they can get brighter and cooler until the middle of the day. They can then start to slowly dim and get warmer again towards sunset. Although the automation sounds complicated, it's actually fairly simple to set up. There's a dedicated Adaptive Lighting custom integration that handles all the automation for you based on the sun's position and your preferences, and there's even a simulator website that you can use to model how your lights will react based on different settings. Trigger an automation when you put your phone on to charge at night Run your bedtime routine automatically At the end of the day, there's a lot of smart home admin to be done. Turning off lights, powering off devices, locking doors, turning down the heating, arming alarms, and more may all need to be done before you go to sleep. A bedtime routine can handle this for you, but the challenge is getting the routine to run automatically at the right time. I don't go to bed at the same time every night. Sometimes I go to bed at the same time as my wife, and sometimes one of us will go up before the other. A simple but effective option is to use the Home Assistant Companion app to determine when your phone is charging. I put my phone on to charge at night before I go to sleep, and while it's never at exactly the same time, it's simple to set up an automation that is triggered when my phone is put on charge after a specific time in the evening. This is a pretty clear indication that I'm in bed, without needing to set up a dedicated bed sensor or presence sensor. Use a calendar to trigger your automations Life doesn't run on a repeating schedule For a long time, I used to hardcode the schedules for my automations into the YAML. The problem is that having an automation that runs every weekday morning is fine until you take some time off and suddenly weekdays aren't workdays anymore. A better option is to use calendar events as triggers. I can add my time off to a Home Assistant calendar, and my automations will only run on genuine workdays. It even enables me to set up automations such as turning the heating off when I'm away but then having the schedule start back up the day before I return so I don't come home to a freezing house. Use geolocation to shut down your home when no one is there The smartphone app is all you need Credit: Home Assistant A smart home can save you a lot of money by ensuring that you're not heating or cooling an empty home. Spending money pumping heat in or out of your home when you're not there to reap the benefits can quickly get expensive. With Home Assistant, all you need is the Home Assistant Companion app installed on everyone's phones, and your smart home can determine when everyone has left the house using geolocation. When no one is at home, heating can turn off, devices can power down, and other energy-saving automations can run. As soon as one person is detected back in the Home zone, everything can start up again. The savings over the course of a year can be significant. Automatically turn on guest mode when visitors connect to Wi-Fi A guest network makes detection simple Credit: Lucas Gouveia | ViDI Studio / Shutterstock Living with someone who's obsessed with setting up smart home automations isn't always easy, but over time, your family can learn to tolerate your all-consuming hobby. They get to learn the quirks of your home, such as never trying to turn on the lights using the actual light switch. Guests don't have the same luxury, and if you leave your smart home running as normal when guests are in your home, they may find themselves plunged into darkness or unable to turn on the TV. A guest mode can fix this problem, but having the guest mode turn on when it's needed can be a challenge. A simple solution is to create an automation that turns the guest mode on when a device connects to your guest Wi-Fi network. As long as everyone in your home uses the main network, this will only happen when guests are visiting. It means that even if you leave your guests alone in the house, it won't shut everything down because all of your family's devices are showing as away from home. Not every useful automation needs a ton of smart tech A smart home can't really be smart without some smart devices, but you don't always need a huge arsenal of devices to run some genuinely useful automations. You may find that using Home Assistant, you can create some awesome automations with the devices you already have.