ᐅ Which tool is best for adding a house to a site plan?

Pencil, set square, and a calculator for converting measurements if the printout is not to scale.

If you already have a .dwg file, you can use LibreCad, FreeCad, QCad, or similar software. These allow you to draw accurately to scale.

Based on my own experience, I would recommend starting the whole process with an "architectural software." I use "cadvilla," which is a user-friendly architectural program for non-professionals but delivers quite good results.

I also started with the DWG plan and imported it. I roughly modeled the neighboring houses, the street, and the sidewalk. I included contour lines and elevation points. You can import furniture from 3D Warehouse. For example, I also imported my own models from FreeCAD. I even did the electrical planning within it.

If you enjoy fully modeling your house, I can definitely recommend this approach.

Sure, just like that, you can learn the basics in a few hours.

Thanks a lot, I used QCad to display the measurements and then switched to graph paper and pencil. It worked well :-)