Home Assistant on a Raspberry Pi 5: the NVMe build (parts list + install)

A Raspberry Pi 5 makes a lovely Home Assistant box: small, quiet, sips power, and has the GPIO header and two USB 2.0 ports a smart home actually uses. The one upgrade worth making from day one is storage. Boot it from an NVMe SSD instead of an SD card, and it behaves like a proper little server.

Build it from official parts: Raspberry Pi 5, the 27W USB-C power supply, the Active Cooler, the M.2 HAT+ and a 2230 NVMe drive such as the Kingston NV3 500 GB. Want a closed box instead? Put the Pi and SSD in an Argon ONE V3 M.2 case. Add a SONOFF Dongle Plus MG24 on a USB 2.0 port for Zigbee.

Specs come from Raspberry Pi, Argon and Home Assistant’s docs.

Pi 5, mini PC or Green?

Pick the Pi 5 when you want a small, low-power box that does Home Assistant and nothing else, with room to tinker: a 40-pin GPIO header for HATs, a power button, a real-time clock and two USB 2.0 ports, which is exactly where HA wants your Zigbee stick.

Pick a mini PC when you want Proxmox and other VMs, more memory, or heavy apps such as Frigate camera detection. The mini PC install guide covers that route.

Pick Home Assistant Green when you want to plug in power and Ethernet and never see a setup screen.

The parts list

Raspberry Pi 5 board. The Pi 5 has a quad-core 2.4 GHz Cortex-A76, Gigabit Ethernet, two USB 3.0 and two USB 2.0 ports, and a PCIe 2.0 connector for an SSD adapter. HA’s Raspberry Pi guide asks for at least 2 GB of RAM, so a 4 GB board is plenty for a typical home. We link the 8 GB board for extra app headroom.

Official 27W USB-C power supply. It delivers 5.1 V at 5 A, and Raspberry Pi recommends it for powering SSDs and other hungry peripherals. Don’t reuse an old phone charger here.

Active Cooler. Raspberry Pi says the Pi 5 performs best with active cooling. The Active Cooler clips on with an aluminium heatsink and a temperature-controlled fan.

M.2 HAT+ and a 2230 SSD. The M.2 HAT+ connects an NVMe drive to the Pi’s PCIe 2.0 connector at up to 500 MB/s. The standard version takes 2230 and 2242 drives and fits on top of the Active Cooler with its stacking header and spacers. The Kingston NV3 500 GB M.2 2230 fits. (The Compact version is the one that fits inside the official Raspberry Pi case.)

Or: Argon ONE V3 M.2 case. The Argon ONE V3 M.2 is an aluminium case with its own NVMe board for M-key drives up to 2280, a drive heatsink, a blower fan, a power button and two full-size HDMI ports. It replaces the Active Cooler and HAT+. A jumper inside lets the Pi start by itself after a power cut. Argon’s fan and button script is written for Raspberry Pi OS, not Home Assistant OS, so plan around the default behaviour.

Zigbee stick. A SONOFF Dongle Plus MG24 on its USB extension, in a USB 2.0 port.

	Build A: official stack	Build B: Argon case
Board + power	Pi 5 + 27W USB-C supply	Pi 5 + 27W USB-C supply
Cooling	Active Cooler	Argon case fan and heatsinks
SSD adapter	M.2 HAT+ (2230/2242)	Argon NVMe board (up to 2280)
SSD	Kingston NV3 500 GB 2230	Kingston NV3 2230 or any M-key up to 2280
Enclosure	Open stack	Closed aluminium case
Best for	A shelf or cabinet, all official parts	A tidy box on a desk or media shelf

Why NVMe over an SD card? HA’s guide asks for an A2-rated card of at least 32 GB when you do use SD. Home Assistant writes history around the clock, though, and an SSD is the sturdier home for that. You also get much faster boots and backups.

Install Home Assistant OS on the NVMe drive

HA’s official guide writes the OS to an SD card. To boot from NVMe, set up the Pi’s boot order first using Raspberry Pi’s NVMe boot steps, then write Home Assistant OS to the SSD.

1. Assemble. Build A: clip on the Active Cooler, fit the HAT+ with its spacers and ribbon cable, install the SSD. Build B: install the Pi and SSD in the Argon case, and set the auto power-on jumper if you want it.
2. Boot Raspberry Pi OS from a spare SD card, with a keyboard, monitor, Ethernet and the 27W supply connected.
3. Check the drive and update. In a terminal, ls -l /dev/nvme* should list your SSD. Then run sudo apt update && sudo apt full-upgrade.
4. Set the boot order. Run sudo raspi-config, go to Advanced Options → Boot Order, choose an option that includes NVMe and reboot when asked.
5. Write Home Assistant OS to the SSD. Open Raspberry Pi Imager, choose Raspberry Pi 5, then Other specific-purpose OS → Home automation → Home Assistant, select the NVMe drive as storage and write.
6. Boot from NVMe. Shut down, remove the SD card, plug the Zigbee stick into a USB 2.0 port on its extension cable and power up. After a few minutes, open homeassistant.local:8123.

Keep the stick away from the SSD. HA’s ZHA docs name USB 3.x devices and ports as 2.4 GHz noise. Use the USB 2.0 port and the extension cable.

Automation: tell me if the Pi runs hot

Add the System Monitor integration under Settings → Devices & services. All of its sensors start disabled, so open the device and enable Processor temperature.

alias: Pi 5 - running hot
triggers:
  - trigger: numeric_state
    entity_id: sensor.system_monitor_processor_temperature
    above: 75
    for:
      minutes: 10
actions:
  - action: persistent_notification.create
    data:
      notification_id: pi_hot
      title: Pi running hot
      message: >
        The processor has been above 75 °C for ten minutes
        ({{ states('sensor.system_monitor_processor_temperature') }} °C now).
        Check the fan and give it some air.
mode: single

Check your exact entity ID and swap it in.

Test it

1. Open Developer tools → States and confirm the temperature sensor shows a live reading.
2. Temporarily change the delay to seconds: 10, then set the sensor’s state to 80.
3. The Pi running hot card should appear. The next real reading puts the true value back. Restore 10 minutes.

The short version: Pi 5, 27W supply, Active Cooler, M.2 HAT+ and a 2230 SSD make a tidy official build. The Argon ONE V3 M.2 turns it into a closed box. Want VMs and heavier apps? Get a mini PC. Want zero setup? Green. Then head to the Home Assistant hub for your first devices.

Still choosing what to buy? Our Pi 5 kit and parts buying guide separates the official open stack, closed-case fit and SD-card bundles before you start assembling.

The same hardware can take a radio job: our Pi 5 ADS-B receiver guide uses Raspberry Pi OS, a USB SDR and a 1090 MHz antenna for a local aircraft map.