I have posted this on the development blog but couldn't upload an image.
It would be great to have a distant terrain that we could turn on or off. If there was a large terrain mesh (enscape can dictate the materials) that just sat in enscape that we could chose to show or not. This could allow the horizon to be broken by distant mountains or a basic cityscape. I know the ground plane can have various textures applied but the flat horizon is not a realistic view in VR. The terrain mesh doesn't need to be super detailed as its just something that the eye/brain accepts without to much scrutiny.
See attached image for a landscape terrain I added in an unreal VR environment. For flat sites the VR view angle only allows for distance viewing over a fence to give you a sense that you are somewhere without being able to see the direct surroundings of the architectural model. This terrain was a 16ha mesh with UV mapped materials. Its polygon count was not crazy as it was built as a background so never intended to be viewed closely.
This will not work in all cases as houses are not always on flat sites but when viewing in VR having a realistic distant horizon is really important.