As with traditional buildings, modular buildings can be used for many different purposes. They can range from portable classrooms to research lab facilities to a medical clinic. Companies in the healthcare, government, education and retail industries often turn to modular buildings for their construction needs.

Unlike traditional buildings however, modular buildings have design constraints. Since the building will be shipped via the road, there are maximum height constraints. Typical ceiling heights are around 8 feet vs. 9 to 10 feet for traditional construction. Companies looking for a building to enclose a much large overhead space (e.g. prefab warehouse, riding arena) will likely fare better with steel buildings.

There are a variety of finishes you can choose for your modular building exterior. They include wood, steel, brick, stucco, aggregate and other exterior siding. You can also customize your exterior with windows, multiple doors, and various roof treatments. Numerous options exist for finishing the interior as well.

As with conventional buildings, you can have your modular building erected so it is flush to the ground or set above ground. To have the building entrance set flush to the ground, you will need a pit-set foundation. You should also consult with a local geotechnical firm to ensure the soil conditions are appropriate for a below-ground foundation. Above-ground foundations will require that your building has ramps and steps to all entrances.

To provide a more custom look, there has been a recent trend to constructing "permanent modular" buildings that require more on-site construction. This translates to having as little as 50 percent of the construction occurring at the factory.