TOPIC:

Add another floor. You should remember that even a bungalow / single story building has 2 floors- the ground floor and the attic. If you add an attic and then add the roof to the attic then you will see the roof no longer sits on the floor.

If you do not wish to add an attic you could also raise the level of the roof. This is achieved in the Roof Construction properties panel . In the General area there is a field "Raise roof level by:" So you just enter the roof height e.g 2.8m and then click on Apply and when you close the dialog the roof will be 2.8m high. You can not use this solution if you have a Gable on your roof, in which case you need to add a floor in order that a wall fills the gable.

See also: Roof on ground

Im have created a single floor building and when I add the roof the roof sits on the floor with all the windows poking through the roof. What am I doing wrong?