but you cannot seriously expect someone to produce images like those linked,
Yes you can. I didn't say it would be easy 
Like any other 3D work it takes a lot of time and effort to get realistic results. Without any other programs you can create the photos like the ones from GaudiGalopin3324 in the first URL (not the animated videos). You have to realize it's mostly the quality of the 3D models and the correct use of lightsources that determine the outcome of a render. You can only render what the model represents. The most difficult part is the composition and using lighsources to get those results. That needs artistic skills independent of the program you use. Add in the need for a fast computer and the patience to wait for (very) long rendering times. That is inheritant to all 3D work.
For KatyFred the first two URLs are the most important. In the first URL GaudiGalopin3324 explains about interior lighting and in the second URL Ceceliabr explains about exterior lighting, each with their own quirks and difficulties.
Creating a house is relatively simpel if you can find all the 3D models you need. For realistic renderings you need to add the lightsources to get those rendering results.
(As far as I know GaudiGalopin3324 only used Sweet Home 3D with the YafaRay renderer for most of the realistic renderings. If you can't find the 3D models you will need to custom create furniture models yourself, which will need something else like Blender. Although you can create great furniture models in Sweet Home 3D it's designed for creating houses, not real-life furniture models.)
----------------------------------------
Dodecagon.nl
1300+ 3D models, manuals, and projects
