The house looks like it has a basement that is partly above ground. I'm not sure what the standard way of achieving that is, but in the past I've used "Miscellaneous" boxes (and wedges) to make large slabs to represent the ground-level, that way the partly above/below ground story can be modeled as a normal storey.
I would concentrate on building the basic layout with the available windows and doors first. Once that's right, you might then replace some doors and windows and other details with custom 3D models. I found Art Of Illusion to be the easiest 3D modeller to get my head around, but that was a few years back, perhaps there are better alternatives now.
By resizing and combining primitive shapes and texturing them, you can often make do without creating a custom model. SH3D comes with a "Miscellaneous" box, I don't think it includes a generic wedge shape, but some folk have contributed wedges (some call them "triangles"). A wedge would be the object you could stretch and attach to a wall to make it look sloped. If you want to build a roof from primitives, a pyramid is also a useful generic shape (the roof plugin didn't exist when I modelled out house - so I used combinations of primitive shapes).
The box is you friend, it can even be used to create an in-model 3D ruler for use when judging heights, lengths, boundaries, etc.
The roof, ground, rear-deck platform, deck steps, and many other elements in the following model have been made using textured boxes, wedges and pyramids.
