I know it probably is not at the top of the list, but maybe a standard to have in mind for later is the KNX standard. It is an open(?) standard that is very popular in europe for new installations (wired), it has support of an extremely wide range of manufactures. (All the big ones in europe, I don't know how much these companies sell in the us though , but the likes of jung, gira, abb, mdt, berker, siemens and so on). It is the closest to a "standard" for home automation on europe.
https://en.wikipedia.org/wiki/KNX_(standard)
