How to add a flat roof and a porch with columns

[aceinc]

I am new to SH3D. I am looking for tutorials, explanations or any ol' help to implement a a drawing which I was able to cobble together in v14 of Punch Home Design. I am looking for a new tool because of my inability to make that program do what I want.

My goal is to do exterior remodeling & landscaping design for this home;

https://www.google.com/maps/place/5700+ ... 80.3286872

And the first step is get the existing structure modelled. It has two flat roof areas, one over a portion of the 1st floor. The second as a front porch with two story columns. I have not found any tutorials or instructions on how to create columns/ & porch or flat roofs. If any one can point me to something which may help I would be appreciative.

[Puybaret]

Flat roofs can be easily designed with rooms creation tool at a higher level.
You can use cylinders for columns or the ones available among the free models.