Tama si van_wilder sa per sqm approx cost ng paggawa ng bahay. Used to be that the second floor is 70% of ground floor per sqm cost. But now, pareho na, including the attic.
Finishing is 50% or more of the total cost now, depending on your taste & preference (used to be 30%). You have a lot of options nowadays on your fixtures et al. Just do not overcommit.