Changes

You have to create a floor plan below you before you can build a roof on any level other than the ground floor. Do this by using a hammer/mallet on a floor and Plan>Floor below, then Plan>Roof. You cannot build a roof on a house underground.

You cannot It can be fiddly to plan a new wall on a tile which has a completed roof structure adjacent. This is due to the model for the roof overlapping the border tile and not allowing making it difficult to be selected. If G was a roof, planned and completed, and you wish to put a wall which is on the same level as the roof on F, C, H or K you will be unable to unless you destroy the roof on G. <table><tr valign=top><td></td><td align="right"> A--B--C--D | | | | E--F--G--H | | | | I--J--K--L</td></tr></table>