When you consider the cost of buying locomotives, construction products like foam board and corflute are incredibly cheap to buy. A huge sheet of corflute (like they use on real estate signs) cost less than $10 at a local DIY store and was large enough to construct several model buildings. What’s more, the material is very strong and very easy to work with.

This video shows how to use corflute board for constructing a model railroad building.

The plan in this video can be downloaded here.