I'm originally from the Coimbra region (Mira and Penacova), and this is my dream!
I'd love to retire back to Portugal and do something similar, but unfortunately, I'd have to hire someone to build the house :-)
But this style of construction is pretty unusual for the region, so you may need someone more specialist. If you need someone let me know though, I can think of a couple of companies.
I can give you more details over email.
The things I think I really got right are: 1) build from new, don’t renovate. And 2) build the whole structure on a platform off the ground. The entire building is supported on 6 steel legs.
Also, solar power + AC is fantastic. A bit of thermal bridging doesn’t seem to matter so much in 40 degree weather when the AC is solar powered :-)