Personally I would not purchase a home that was configured with nest or other home automation equipment for several reasons.
1) It's a huge security risk. When you buy a home the first thing you do is change the locks because you don't know who the previous owner may have once loaned keys out to. Now you have a bunch of computers in your house giving remote access that may or may not be giving other people access and you can't tell.
2) Most consumer home automation systems have incredibly bad failure states. Those wirelessly networked alarms? When you cheap Chinese wifi router catches fire from a faulty power supply the failure mode is that you die. That's a pretty big oversight. Remember when NEST pushed an untested software update remotely and caused dozens of houses in the Northern Midwest to lose heat in the middle of winter and then be destroyed by broken pipes?
3) Vendor lock in. I don't want the previous owner to lock me into a line of products. Period. I'm sure everyone here remembers when Phillips decided that their smart light sockets would embrace DRM and only accept Phillips brand LED bulbs. They backed down but it is bound to come up again. Not to mention simple incompatibility between competing products and stacks.
4) It's just a damn pain to use most of the time for gain that can be measured almost entirely in novelty factor.
It's not that hard to change a thermostat and smoke alarm. "Dumb" smoke alarms and thermostats are very inexpensive and easy to install. Buy a home for the structure and location. You can always change the few things you don't like.
If it seems to be a bit much just be glad you aren't in Massachusetts where they are currently trying to get arc flash rated 110V breakers added as a requirement to the electric code.
...however, the code (at least back in 2002) specified protection of all electrical outlets. Receptacles are plugged into outlets. So are hired wired lights, smoke detectors, etc. An outlet is "A point on the wiring system at which current is taken to supply utilization equipment."
This means that any literal reading of the code requires arc-fault breakers from a practical perspective since even the outlet into which an arc-fault receptacle is plugged requires protection upstream from the receptacle. On the other hand, building departments often make code interpretations that are politically expedient and that's why some jurisdictions may allow arc-fault receptacles as a means of code compliance.
AFAIK the code also requires the wiring itself in those places be AFCI protected, since the (immediate) goal was to avoid smoldering fires in the wall where people sleep. This would imply the simplest route is an AFCI breaker for the whole branch circuit, although it was (is?) permissible to run metal conduit up to the first receptacle and have that do the AFCI.
Would have loved for the NEC to require that the code on AFCIs was technician-upgradeable and some general sense of open, but I'll just go back to banging my head against the wall now.
Are you just talking about MA adopting newer versions of the NEC that require AFCI [0] more places, or is there really something new related to arc flash?
[0] A proprietary software hellhole, like everything else these days.
I have some that have "long-term tamper-proof batteries" (I think they last 5 years or something)... and _somehow_ are "interconnected" (so they can all trigger each other) which was a requirement. They don't use _my_ wifi, I don't know how they are interconnected without wires exactly (or if it even really works). I'm not worried about it, but it passed inspection.
Do … do people realize that power cuts occasionally coincide with house fires?
I really don't care about a backup mesh network as long as they are loud enough when there is no network.
A few days later I was at a bar while their alarm system was getting inspected. I asked one of the pros about the situation and he told me that Nests require a working internet connection in order to pass state inspection, and all of the alarms have to be Nest.
I wish I either removed everything before putting my house on the market, or excluded them all from the sale. The buyer was confused, and the Nest smoke alarms needed to be replaced prior to closing.
The Nest smoke alarms were fine, but due to local fire codes, I needed to have wifi running at inspection time and all of my smoke alarms had to be Nest. I was replacing one a year and still had a few "dumb" smoke alarms in the mix. Unfortunately, my realtor advised me poorly in this situation when I told him my plan was to take the smoke alarms and thermostats with me.