Hello!
No problem, i will create .exe rather fast. I prefer .fbx file of the house. About lighting and effects - no problem, all light will be baked in high quality, fog, atmospheric dust, etc.
I will send you druft builds every day and will aplly your commments. I dont need prepay, just usual milestone.
As a portfolio - i'm Unity3d developer for 6 years, and have 2 years experience in VR, worked with all VR devices, such as Oculus DK1, DK2, CV1, HTC vive, Gear VR.
Hope you will like my work! :)