ArchViz- how to show the real world view?

I am going to use UE4 for archviz and wonder how to show the real view from the future buildings.

All the examples I have seen are shown in extremely wide, open landscapes or with a distant cityscape photo outside the windows. This isn’t really showing the future truth to a potential buyer for any of my projects.
For still picture visualizations it is easy to use a background photo, but how do you solve this when the user will be walking around in your model?