Most "subscription-free" alarm systems still send your data to manufacturer servers, leaving you vulnerable to outages, privacy breaches, and surprise fee changes. In this episode, Chelsea Miller breaks down exactly how to build a truly local security alarm system that costs nothing per month and keeps every byte of data on your own network. After three months of testing various configurations, she walks through the complete setup process—from choosing the right Zigbee sensors to configuring Home Assistant automations that trigger faster than cloud-based competitors. This guide is for intermediate DIYers comfortable with basic networking and configuration files who want genuine control over their home security.

• A fully local alarm system can trigger alerts in 200–400 milliseconds, significantly faster than most cloud-dependent alter ...