After spending hours researching and experimenting, I finally managed to set up a seamless automation system in my home! 
The goal was to create a system where opening a window would automatically adjust the HVAC settings to maintain a comfortable temperature, while also turning on motion-activated lights for safety. I’ve been using a combination of KNX and BACnet systems, but the integration with Home Assistant has been key.
Here’s what I did:
- Window Sensors: I installed window sensors to detect when a window is opened or closed.
- HVAC Automation: Using Home Assistant’s automation feature, I programmed the system to raise the temperature to 26°C when a window is opened in the summer, ensuring the HVAC doesn’t overcool the room. It reverts to the original temperature after a set period if the window remains open.
- Motion Lights: I set up motion sensors near the windows. When motion is detected after sunset, the lights automatically turn on for 5 minutes, providing just enough time to secure the window without wasting energy.
The best part? All of this is managed through a single automation blueprint, making it easy to replicate for other rooms! 
I’d love to hear how others have tackled similar challenges or if there are any tips to make this system even more efficient. Let’s share our smart home hacks! 