== Skill needed ==
More skill is required per level, see the table below. Only the first (ground) floor planning needs 1 skill per wall and 1 skill per tile. With 20 skill a roof may be placed over the first floor, but not an opening or floor above. For upper floors, the roof counts as a floor (although it may have less of a skill requirement than an opening or floor above- unconfirmed).
{| class="wikitable"
|| <24 || 3 ||| || 8 ||| || 13
|-
|| || 4 ||| <77 || 9 ||| || 14
|-
|| || 5 ||| 90 || 10 ||| 99 || 15