How to make power infrastructure for USB powered devices

Hello,

I hope I will start to build my house soon. I would like to put my DIY home automation there. I have still a lot of time, but I want to gather all the good ideas.
Today I started to think about power distribution for devices like smart Z-Wave sensors. They are working OK in my flat, but I am powering them though USB port of my PC. I cannot imagine to rely on batteries, having to remember about charging them regularly…
Question is how to distribute low voltage power to them around whole house. My initial plan was to put Ethernet cable everywhere, then power it by some low voltage power supply.
How do you solve this issue in your houses?

Be careful with ethernet carrying low voltage. You will get voltage drop over long distances due to the thin wires. Maybe if you twisted 1/2 the pairs for + and the other half for -, that might work better.

POE works because it pushes 24 to 48 volts at lower amps and then the receiving device converts down to 5 or 12 volts.

If someone has a good solution, I’d like to know too. Some of the devices I’d like to use in the future I’d like to wire up as well.

If you are using POE switches, you can get POE to USB splitters, i use one for powering my tablet on the wall

You mean something like this: https://www.amazon.com/micro-USB-splitter-adapter-Raspberry-IEEE802-3af/dp/B0108TD78Y
In theory OK, but the size is not so small. I will have to think how to hind it in the wall.

I just use 240Vac to 5Vdc adaptors such a phone chargers, located at each of my z-wave devices. In my last house (I’m currently renting so not an option) I installed outlets in the ceiling space above each z-wave motion detector and plugged the phone chargers in up there. It worked perfectly. In my rental I am just using the regular wall mounted outlet with long USB cables since its only a temporary situation.

I am trying to stick to USB wall plugs or power boards with USB ports where possible. Additionally, I use a 12V AC “garden light” system, running cables under my house to distribution points and then connect a 12VAC-to-5VDC converter with USB outlets for flush-mounted sensors or wall-mounted tablets.