TLDR
- Use one independent Home Assistant server in each physically separate home. The official Companion app can connect to both.
- A detached garage or guesthouse can usually share one server when it uses the same reliable local network and your Zigbee, Z-Wave, Bluetooth, or Wi-Fi coverage reaches it.
- Avoid making lights, locks, heating, leak alerts, or other important routines at one property depend on an always-on internet or private network connection to another property.
- Main caveat: Home Assistant Cloud needs a separate account and subscription for each installation. A combined dashboard requires optional community software, not a built-in merge.
Use one Home Assistant server in each separate property
If the properties have different internet connections, put a small Home Assistant computer in each one. Keep that property's devices and essential automations on its local server. Then add both servers to the official Home Assistant Companion app on your phone. You get simple access to both without making one house's basic operation depend on the other house being online.
Home Assistant users often call each running installation an instance. Two instances mean two sets of settings, devices, automations, updates, and backups. That is a little more maintenance, but it creates a useful boundary: a broken private network connection, often called a VPN, an internet outage, a restart, or a bad update at the main home does not have to take the second home's local routines down with it.
The main exception is a detached garage, workshop, or guesthouse on the same dependable local network as the main house. One server can be simpler when the link between the buildings and the device-radio coverage are both reliable. If the second building has its own internet service or must keep working when that link fails, treat it as a separate property.
The practical rule: if a property should still look after itself when the connection to your other property disappears, give it its own local Home Assistant server.
One server or two? Use the property boundary
| Your setup | Usually choose | Why |
|---|---|---|
| Main home and vacation home | One server in each home | Each property can keep locally controlled routines running when either internet connection or the link between sites fails. |
| Home and workshop across town | One server at each site | Local device radios, discovery, and automations stay close to the equipment they control. |
| House and detached garage on the same local network | Usually one server | The buildings can share one reliable inside network if device and radio coverage is designed for both. |
| Guesthouse with a separate internet service | Usually a separate server | The second internet connection is a useful sign that the building should remain independently operable. |
| Two floors or family zones in one house | One server | Use areas, floors, dashboards, and household accounts to organize one physical home instead of duplicating the whole system. |
This is a recommendation, not a Home Assistant licensing limit. A single server can control devices at two sites when the networking and integrations—the software connections to devices or services—allow it. The tradeoff is that the cross-site connection becomes part of the control path. If that link fails, the central server may no longer see or control the remote property's local devices.
Why a local server at each home is more dependable
Local routines do not wait for the other property's internet
Imagine a leak sensor in a vacation home turning off a local water valve. With a server in that home, the sensor, decision, and valve can stay on the local network. With one central server hundreds of miles away, the same action may depend on both internet connections and the tunnel joining them. Keeping the decision local removes that extra failure point, although every actual device and integration must also support local operation.
Zigbee and Z-Wave radios belong near their devices
Zigbee and Z-Wave devices talk to a coordinator or controller radio at the property. They do not reach a USB radio in another city through the internet. A separate server lets each property have its own local radio and mesh. Wi-Fi and cloud devices can sometimes be reached across sites, but that convenience does not make the remote internet link dependable enough for an important routine.
Maintenance problems stay contained
Separate servers let you restart, update, restore, or troubleshoot one property without deliberately interrupting the other. They also make a future sale or handoff cleaner: the second property's devices, history, and automations are already grouped with the server that belongs there. Use the Home Assistant hardware migration guide if an existing installation must move before you split the sites.
When one server for two buildings is reasonable
A garage, garden office, barn, or guesthouse can share the main home's server when it is truly part of the same local system. That normally means the buildings use the same dependable router and network, the network link between them is suitable for the environment, and every required device radio has reliable coverage. One server is simpler to update and back up.
Still ask what happens if the cable, wireless bridge, or outbuilding network switch fails. A garden light being temporarily unavailable is different from a freeze alarm, door lock, heater, pump, or livestock system becoming unreachable. Keep physical controls and independent safety devices for anything consequential. Our guide to what happens when Home Assistant goes down helps identify those fallbacks.
Set up two homes in six practical steps
- Install one local server at each property. It does not need to be identical hardware, but each server should be able to run its own home's integrations and automations. If you are choosing hardware, start with the local smart-home hub options rather than stretching the first server across the internet.
- Pair devices with the server at their property. Put Zigbee and Z-Wave coordinators at the site they serve. Keep important triggers and actions inside that same installation whenever possible.
- Give each home an unmistakable name. Use names such as “Main House” and “Lake House,” then check the location, time zone, and units on each installation. Put the property name at the start of important alert titles.
- Add both servers to the Companion app. In the app, open Settings → Companion app → Add Server. Servers on the same network can be found automatically; otherwise enter the secure address you configured for that property.
- Choose safe remote access for each home. Home Assistant documents Cloud as the easiest secure option for most people and a VPN as another route. Do not expose an unencrypted Home Assistant port and assume it is safe. The remote-access guide compares the safer paths.
- Back up and test each home separately. Make a full backup for both installations, keep recovery copies away from the server they protect, and test a harmless local routine while the property's internet feed is disconnected. Follow the Home Assistant backup checklist for each server.
How the Companion app handles multiple homes
The official Companion app supports additional servers. Each server remains separate, with its own login and dashboard. The app also lets you decide whether phone sensors are sent to each connected server, although its documentation says some sensor settings are shared across the connected servers. Review location and privacy settings instead of assuming every phone sensor should go to every property.
Notifications are sent by the installation that created them, so make the property obvious in the notification title: “Lake House: leak detected” is much safer than “Leak detected.” If a notification link should open a particular dashboard, the official URL-handler documentation lets that link name the intended server. Without the server name, the app may ask which one to use; some other link actions use the first server in the list.
Do you need two Home Assistant Cloud subscriptions?
Only if you want Home Assistant Cloud on both installations. Nabu Casa's current policy says every installation using Cloud needs its own account and subscription. Reusing the same account on two installations can leave only one with active Cloud service, so do not treat one login as a household-wide multi-server plan.
You can use Cloud at one property and a securely maintained VPN at another, or use another supported remote-access design. That choice changes how you reach the dashboards from outside; it should not change the goal of keeping essential automation logic local to the property.
Can two servers appear in one combined dashboard?
The supported simple option is to keep both servers in the Companion app and open the one you need. Home Assistant Core does not automatically combine separate installations into one dashboard.
The community-maintained Remote Home-Assistant custom integration can copy selected entities from remote installations into a main one. It is installed on the participating servers through the Home Assistant Community Store (HACS) or manually, and it is not the same as built-in Home Assistant support. If you use it, mirror only the overview information you actually need and test it after Home Assistant or integration updates. Keep the remote home's leak response, heating protection, locks, and other essential routines on its local server so a broken connection or custom integration does not remove the useful action.
Test the boundary before trusting it
At each property, disconnect only the internet feed while leaving the router, Wi-Fi, server, and local devices powered. Try a few non-critical local controls and automations. Confirm that the second property continues working without the first, then restore the connection and check remote access and notifications.
Do not test with a live security event, occupied heating emergency, active water leak, or a door that has no ordinary key. Home Assistant is useful control software, not a replacement for code-compliant alarms, physical locks, manual shutoffs, or other independent safety equipment. Write down which features are local and which still depend on a vendor cloud.
Frequently asked questions
Can one Home Assistant server control two homes?
It can if the server can reliably reach every device and integration at both sites. For physically separate properties, one local server per property is usually safer because a failed internet or VPN link will not stop that property's local automations.
Can the Home Assistant app connect to multiple homes?
Yes. In the official Companion app, open Settings → Companion app → Add Server. Each property remains its own Home Assistant installation, and you can open the server you need from the app.
Do two Home Assistant servers need two Cloud subscriptions?
Only if you want Home Assistant Cloud on both. Nabu Casa says each installation using Cloud needs a separate account and subscription. You can instead configure another secure remote-access method, such as a VPN, if you are comfortable maintaining it.
Does a detached garage need its own Home Assistant server?
Usually not when the garage is on the same reliable local network, the required device radios reach it, and a link failure would not create an unsafe situation. A distant workshop on another internet connection should normally have its own local server.
Can two Home Assistant servers share one dashboard?
The official Companion app can hold multiple servers, but Home Assistant Core does not automatically merge them into one dashboard. Community custom integrations can copy selected entities between servers, but keep essential automations local to each property and treat that linking as optional.