Some houses have been built without basements, so some people give up on electric train track layouts or model railroads.
If you are going to build a train track layout or a model railroad, and there are no basements, you can use or build a second or third floor on an existing house.
If the house has a roof that is needing repair, that would be the time to add a floor just for the train track layout or model railroad.
Andrew
Falcon Service