My guess is that the house is inhabited, the owners are probably poor, but have lived there for probably many decades, and have no intention of leaving. Their h

My guess is that the house is inhabited, the owners are probably poor, but have lived there for probably many decades, and have no intention of leaving. Their heirs won't have enough money to fix it up either, unless they emigrated to Luxembourg or something, and may very well keep living there, since they can't afford anything closer to Lisbon. The problem with Portugal is quite often just a simple one: lack of capital. By the way, the lower walls may be stone, but the rest is often just brick with terrible cement slapped on top. Water infiltration issues are rampant, especially in a humid area like Sintra. Mold is certainly an issue, and the solution often requires removing all the cement and reapplying it, which ain't that cheap.