Selling

[marvukis]

Is the making home design, we can sell these designs ...? [B-)]

[Puybaret]

Software distributed under the GNU GPL license, like Sweet Home 3D, can be used for commercial purpose, including selling the designs you will create with it.
If your designs use some models available from 3D models page (like all the examples in the gallery), you'll be free to redistribute and/or sell these designs, if you should add an attribution to their authors as stated in Free Art License and Creative Common license.
If your designs use some models coming from other places like Google Warehouse, please check the license on their web site first.

[marvukis]

I created these designs with the thought of my own imagination and not look to the previous design but provide guidance in making the design of the house.

and also if the house is where the design is finished in need details about the house ..??

[Puybaret]

If your homes / plans / designs / projects contain only levels, walls, rooms, dimensions and texts, there's no problem to sell them or redistribute them. But I guess you added at least a few doors, windows, staircases and other kinds of furniture, right? In that case, you should take care of the license of the 3D models of each object you added. For example, the models coming from ArchiBit are distributed under Creative Commons BY-NC-SA license which forbids you to use them for commercial purposes.