Modular Mini Storage offers Fast-Build Panelized Construction kits to the self-storage industry. They claim that more customers are including office/warehouse units in their mix.

From their web site http://www.modularministorage.com/ :

Office/Warehouse (Flex-Space)

-An EXCITING new opportunity for self-storage owners.
-MODULAR's panelized building system allows you to develop office/warehouse space at a lower cost than other building systems.
-Our pre-fabricated walls support the roof structure.
-Eliminates need for rigid iron frames.
-No cranes required for erection.
-Our walls distribute roof loads so foundations are less complicated and less expensive.
-Steel stud wall framing already in place for:
-Insulated office and warehouse walls,
-Demising walls,
-Firewalls, and
-A multitude of architectural finishes.
-Pre-fabricated walls include framed openings for windows and doors.

Perfect for smaller sites or part of a larger complex. These units are perfect for contractors, small businesses, and people needing a larger space. Spaces are leased by the year and require less intensive management.Each building is custom designed to meet your needs, and our delivery time is much shorter than the rigid iron folks.

Office/Warehouse developments can be built on smaller properties not well suited for self-storage. They can be incorporated into larger projects to make better use of street frontage or flag lot locations. Multiple tenants spread your risk. Longer term leases minimize management costs.