The word house is used as a synonym for a property. If your parents live in a flat, you will say « I'm going to eat at my parents' house on Saturday ». Even if you live in a 25 sq.m. studio, after a day's work you will say. “I can't wait to get home! ». The language is flexible, your house is your home and you can call it as you want.
But a house-house is different. If you ask a kid to draw a house, he will do something like this: a two-storey building with an attic, surrounded by a very green garden and a blue sky with a few clouds. Surely you have made a drawing like this when you was young. That's a house-house and the good news is that they exist, and here you have the proof.
Ferrocarriles: S1 Les Fonts
Túneles: 15 min BCN