I have one of the buildings in the series built from various modular sections and they appear to be HO scale as far as the rest of my buildings. I noted that the detailing is up to the number of modules used as there are all sort of possibilities. I built my one building as a general delivery and storage building with two other building wall combination sets and detailing modules available. An entire city block is possible. As with many of these types of kits I attached the clear plastic windows into the inside of the insets first and painted the exterior before seating the window inserts which where painted as well. Although the molded colors are OK, I would recommend that one would use colors other than tan and green. This is fairly simple yet effective way to build up a city scape for any modeler.