Eleven apps, one house.
How I went from a phone folder full of smart-home apps to one bus, one brain and one database. What each app turned into, what the house looks like a year later, and what broke on the way.
Then → now
The "Home" folder, 2024 → 2026In the last place we lived, my phone had a folder called "Home". Eleven apps in it. Each one owned a slice of the flat: blinds in Tahoma, lights in Hue, plugs in Tuya, sensors in Aqara, the front door in Nuki, the washing machine in SmartThings, voice in Alexa, cameras in Apple Home. None of them knew the others existed.
It worked the way a patched thing works. Every scene that crossed two brands needed a bridge, and every bridge was a cloud account that could change its terms, break its API or go dark. When one did, I debugged it standing in the hallway with four apps open.
Moving house was the chance to do it once, properly.
The plan: photograph the house before touching it
4 domains · 12 subsystemsBefore buying a single device I made a board. Four domains, twelve subsystems, two columns: Today and the target. Under Today went a photo of every panel, box and keypad the house came with. A year later, nine of twelve live in one place. Three were left alone on purpose.
Four layers, one job each
Bus · hub · lake · brainKNX
Lights, dimmers, blinds and presence detectors, wired, no app, no cloud. If every computer in the house dies, the switches still switch. That is the whole point of a bus.
Home Assistant
A Raspberry Pi 4 in the technical room. Every device ends here over local protocols. It runs the reflexes that must fire in milliseconds: a door opens, a light follows. It executes. It does not decide.
Postgres
Every hourly reading lands in the same database that holds my training and my money. The house is a dataset, and nobody types into it: agents read it, loaders write it.
The agents
Headless Claude Code processes on the Mac. They read the lake and the hub, compare against rules written in plain markdown, and act: a push, a restart, a change in the heating curve. The same swarm that runs my mornings.
Home Assistant is excellent hands. It is a poor brain: it knows the state of 1,839 things and the history of none of them. The decisions that need memory, a baseline or a comparison across weeks live one layer up, where the rules are a paragraph of prose I can edit from my phone.
What happened to the eleven apps
11 → 1| App | It did | It is now | ||
|---|---|---|---|---|
| Nu | Nuki | The front-door lock | DoorBird with fingerprints, logged into HA; a Shelly sensor on the door. | GONE |
 | Hue | Colour and dimming | KNX dimmers dim; the Hue integration sits ignored in HA with zero entities. | GONE |
| So | Tahoma | Blinds | KNX. 26 covers in HA, one of them a Shelly on the kitchen blind. | KNX |
| dv | devolo | Wi-Fi mesh and plugs | UniFi, wired. Fast roaming switched off on purpose because the DoorBird hated it. | GONE |
| Aq | Aqara | Door, window and climate sensors | Still here, through Matter. Five hubs remain; their sensors reach HA locally, 134 Matter entities in total. The app is for pairing, nothing else. | HARDWARE |
 | Shelly | Relays | Native and local. Four devices: three door sensors, one cover. No cloud. | HARDWARE |
 | SmartThings | Everything Samsung | Only the washer and dryer, so the laundry view knows when a cycle ends. | HARDWARE |
| Tu | Tuya | Cheap plugs and cameras | Nearly gone. Two OSAIO cameras still speak only Tuya; they move or retire next. | GOING |
| Sb | SwitchBot | Buttons and curtains | Nothing here needs a robot finger. | GONE |
 | Apple Home | Cameras, some scenes | Being emptied. Two Eve cameras and an Aqara G3 are left; the plan is to pair them into go2rtc so Frigate records them like the other ten. | GOING |
| Ax | Alexa | Voice, music | Voice only. Six Echo Dots for "turn off the kitchen" and timers. They control nothing directly; HA does. | VOICE |
What came in that was never an app
Local firstThe rule for everything new was the same: local first, cloud only when the device gives no choice.
- Ten cameras in Frigate on a separate NVR: object detection, face recognition for the household, 30 days of retention. The DoorBird and the fingerprint reader feed the same log.
- Two Teslas through the Fleet API: doors, windows, charge, trips into the lake.
- Robot mower, Gardena irrigation, Eight Sleep, the e-bike, the gym projector. All in HA, all in the brief when they matter.
What broke
A clean architecture is not a quiet one- Editing Home Assistant's storage files by hand stopped the whole house for 25 minutes. Never again; everything goes through the API now.
- The DoorBird is Wi-Fi only and cannot be cabled. It drops the network a few times a month. When it hangs, only a power cut brings it back. It is hanging right now, while I write this from Japan.
- Frigate was writing 193 GB a day because three cameras detected on a deformed image and the hardware acceleration was crashing ffmpeg 1,500 times a night. Both found by reading the data, not the UI.
- The 2.4 GHz band carries nine cameras, five hubs, six Echos and the appliances. It is full by design. Cabling the garage cameras is the next physical job.
- Matter is multi-admin but not multi-everything. It brought the vacuum and the Aqara sensors in locally, and it still cannot do a camera.
The rules I'd give someone starting today
Eleven apps, one house. The phone folder is gone. The hallway debugging is gone. What is left is a bus, a brain, a lake, and a family that asked for 24 degrees and got it.