As far as I know you can only export 2D DXF files from 3D Home Architect. A year or so ago I tried to export a house I created and could only export the 2D floor plan. So what I did was convert the floor plan to an Adobe Illustrator file and extruded it in the spline modeler. Then I cleaned up model in the vertex modeler and added the doorways, windows and roof. It sure would have simplified things if I could have exported a 3D file from 3D Home Architect