For me and my own HA install, I accept I will have to revert everything to how it was when I bought the home, which is itself a really tragic statement on the state of home automation in 2022. I get satisfaction from running it, but it does require running. It is not an "appliance", and there are still no real building codes/standards for ensuring these things stay compatible for years to come.
Similarly, if the seller tried to convince me to take a house with their own home made HomeAssistant setup, I would likely request it be removed completely before I closed the sale, regardless of any perceived quality of the work. If nothing else, I couldn't trust they hadn't left their own remote access ability somewhere in the stack and I don't have time to audit what might be years of quite hacky integration work.
There is an old saying, "Never sell a car to a friend". Home assistant is like that, but you should never sell it to anyone, regardless of how good you think you've got it running today.
I am close to adding an iot wifi access point that can remain with the home. All gear connects to it and then up to whatever internet is present.
My HA currently runs in a vm but seeing the fanless devices (or laptops) is encouraging. Chrome books with 8 gb of ram seem like a good candidate to become a server appliance.
Add to it a few tablets and it’s not so bad. Documentation can go a long way as well even if it is for tenants.
The home assistant blue or yellow device is also intriguing for that reason. If it had a touchscreen built onto it it would be one step closer to being self sustained.
Until there are proper standards that we can rely on to last for decades plus for automatable home devices in general, Home Assistant will never be truly self-sustaining. Almost all of its integrations rely on unofficial API access, those APIs change often enough to requiring patching etc. Finding a cheap reliable machine to just run Home Assistant has never been the problem either.
Home Assistant doesn't try to solve the elephant in the room: the complete lack of any standards in the industry, instead it tries to patch over it through regular software updates to keep everything working together.
No matter how good you have Home Assistant today, you are just one bad release or API change from any of the hundreds of smarthome product vendors breaking it - it is completely outwith your control. It doesn't happen super often, but it's often enough that I'd think someone a little silly to include it as part of a home sale process. Almost zero of HomeAssistants integrations are supported by the vendor, some vendors are even actively hostile towards efforts to use their APIs in HomeAssistant.
I'm secretly hopeful that the new standard, Matter, finally solves some of this for the long term, especially with Google/Apple buy in, but will probably be years before we see Matter devices hit mass market:
Still, some manufacturers like Lutron makes some nice switches however their cloud connectivity is not something I wish to keep a dependency on for the initial setup. There's simply no reason to make it mandatory.
Another piece of useful gear that is being discontinued is the Logitech Harmony Hubs... no replacement really, and the existing gear will be supported for an unknown period of time. Would be a great candidate to open source.
A few months ago I sold a house a house with lots of Insteon stuff, and I left almost all of it in place. Partly it was because we sold quickly and I didn't have time, and partly because it was 9+ year old gear anyway. Insteon has the benefit that the keypad scenes and switch-to-switch links work without a hub. I took my hubs (ISY99 and HomeAssistant) which means no automations or timers.
I would have left the ISY99 if the new buyers had asked, but I didn't want to provide tech support of any sort for it. The downside of this type of gear compared to (the orders-of-magnitude more expensive) commercial stuff is you really have to know quite a bit about it to manage it. For the most part there's really not any local trades people you can call for service, and frankly, it's not worth the headache as a seller to even try to explain any of this.
In my new (current) house I'm in the process of installing Zwave switches. I think they're pretty hub-dependent, which is definitely a downside compared to Insteon for resale. I am really not sure what I'll do when I move, but hopefully it will be several years before that's an issue. I am fairly certain though that HomeAssistant (both software and ecosystem) won't be at the point where I could just leave it for the new owners and not cause more trouble for myself than it's worth.
When we leave my plan is to leave the Caseta system in place. Some of the devices are wireless and some switches have batteries (CR2032). We did this so we could put switches in locations you would normally have switches in a modern home without having to tear out the walls and rewire an 80 year old home. Ripping the system out is not an option, and I'm ok with that.
Everything else is going with me. All the z-wave outlets, bulbs, timers, sensors, etc. will still be useful in a new home. I've saved all my old outlets so it will be an easy swap switching the new back to the old.
The only thing I'm unsure about is the Wyze camera/security system I am currently building out. My expectation is that by the time I even think of selling my home it will be obsolete so I'll probably just leave it for the new owners to worry about.
Usually its either the relay refusing to switch on or off. Or its able to switch on and off via the app, but not via a light switch that it was happily doing the day before. Or it disappears off the WiFi and refuses to connect no matter how many resets / power cycles are done.
After replacing 10 or so of them, I decided it was easier to rip them all out.
So hard-resetting them is often the only option, which is often a time consuming process in itself (I'm looking at you Insteon) and throws away the configuration.
I didn't even attempt to leave the HomeAssistant-based stuff in place.
Not to mention the convenience of having the ability to have e-mails sent to whoever happens to be resident at that property and keep a history that can be transferred. I.e. maintenance invoices, remodel invoices, appliance receipts. Then when you sell the house the new owner will get all that info.
Otherwise the default if not excluded in most contracts in the US would be to leave nearly all of it. Kind of like keys, even if something is not permanently affixed to the home it is "annexed" and transferred with the home when it is part of the customized home automation system. So the thermostat is part of the real estate even though it is wireless. The motion sensors and door bell are both annexed, and fixtures as they are attached with a wire. The lightbulbs are one thing that is probably not annexed or a fixture, it is a grey area, but potentially are addressed specifically in the contract like curtains.
This is just a thought at this point, frankly, so there are obviously some gaps that need to be worked out.
I think "How Buildings Learn" by Stewart Brand covered it.
Everything was pretty easy to remove and take with me to our next house.
It was fairly easy to just factory reset everything and walk away, but yeah if there was an actual PC/RPi and a user-managed software stack in the picture, I could picture it being a real headache to sort out.
I moved in to a house with a Nest and it wasn't too difficult to set up again after doing the hard reset. Would've been much more awkward if I moved and there was just no thermostat...
If I bought a home with smart doorbells and cameras and other stuff, I'd rip it out and replace it anyway. Who knows if the previous owner still has them on their account, or can access them in some way?
It has long been common wisdom that you should rekey or replace the locks when you buy a home. The same logic applies to smart devices.
Hubs probably go with previous owner. Turn-over too complicated - just unplug it and take it.
Something like a Nest (or anything else with direct cloud integration) is a bit more complicated. You'd either have to unpair it from your account or replace it with a dumb thermostat.
Both doors were Z-wave enabled locks, left both of them as I bought updated ones for the new house
Left 2 IP Cams (with manual and details) that were not smart to take down, and planned on switching at the new house.
I took all the Ubiquiti wifi gear, all the home automation hubs and anything I could EASILY reuse.
My experience with house shopping in LA is that you've got no leverage to question why some panel is missing or some disconnected wires are sticking out of the wall.
in Texas anything attached stays so even lightbulbs but you can also exclude anything explicitly.
If I ever sold this place, I would move out most of my ha and automation stuff first.
Even a generic hot cold thermostat is pretty cheap and easy to put in.
Would probably leave recessed touch screens though.
This has increasingly been on my mind. I've no desire to sell soon, but there's a Nest doorbell that is wired in, so it stays. A Nest thermostat, which I could remove but when I got the boiler I chose to not have the control panel extra with timer as I knew I had Nest. Then the lighting, the motion sensors... should I take the few thousand GBP worth of Hue bulbs? That feels like a yes, just put in the cheapest bulbs.
And so it begins... some things stay, some things go, and the tooling is the hardest. This person has touch screen control panels and Home Assistant. Even if you left it behind, you'd need to transfer the knowledge around it too. But remove it, and the house goes beyond dumb in many ways.