I thought I revive this thread, with a bit of opinion of mine.
I am owner-building a house 100km west of Brisbane… not your average house, but a passive house, yes, in Queensland 
It will sit on 10 acres, have 12kW of PV panels, 2 x KACO 6002, and aSelectronic SP PRO GO with 10kW in LiFePO4 batteries… pretty much self-reliant… using the gird as back-up only.
I will import most of my ‘stuff’ from Germany; e.g double-glazed windows, water storage tanks with multiple heat exchangers, ventilation, some appliances, combustion heater, etc. – all put in a 40-foot container and shipped over.
Yes, I am an ex-German, who migrated 20 years ago… the point being, I can culturally connect to the boys over there and their approach to things.
While lots of wiring tasks can be done in Germany, it is illegal to do any (above low voltage) work as an unlicensed person. Even data cabling needs to be done by a licensed cabler.
All pretty much a joke (in this nanny country), plus, anything is actually darn expensive here.
My point: I have the electrician run the power points, everything else will be low Voltage, which I can (and am legally allowed to) install. There won’t be light switches; all controlled by ambient light sensors, time of day, motion and presence sensors.
As for the resale value of homes; this will be my last home (will only get out in a coffin), as such, I couldn’t care less what the resell value --, or possible off-putting reasons for any potential buyer may be.
My approach is almost exactly what CeeCee described in Full house rebuilding incl. home automation installation - my approach
(what a co-incidence)
What I will do though, is documenting the installation, components and code; provide redundancy hardware (spare rPi, Arduinos), and never upgrade after the system is full functional (locked down).
While I sincerely wish that openHAB will be around in 20 years, in reality, this is a total unknown, hence the above approach.
All the best to my fellow Aussies and their approach to home automation