If you want a higher degree of control over the creation of houses etc, you can set the tiles to be a quarter of their original size.

To do this, open up the cheat box "Ctrl+Shift+c" and type in

"setQuarterTilePlacement on"

then exit the cheat box and press Ctrl+F to engage this cheat (this is crucial as the cheat doesn't work without pressing ctrl+f)