Many people are considering modular construction when embarking on a new home or light commercial building project. Modular construction has evolved by leaps and bounds over the past decades, gone are the days of modular construction being simply another name for trailers. Today when a modular construction project is completed most people would be hard pressed to tell the difference between a modular building and a « stick built » building.
Modular construction offers many benefits over traditional construction including an accelerated construction schedule; traditional construction requires that the foundation be installed first before the building can be built. Using modular construction, you would be building the building in the plant at the same time the foundation is being installed in the field; once the building modules are delivered the main structure is completed in a matter of days versus weeks in traditional construction. Other benefits include reduced weather delays, site vandalism and theft to name a few.
Those that take the modular concept one step further and decide to use shipping containers as the basis for their modular may find even greater advantages – if they are careful.
Modular container buildings use the architecture of 40′ x 8′ and 20′ x 8′ shipping containers as the basic building blocks for their project. While standard modular building modules can be constructed to almost any desired dimensions and the modules attached to one another for a complete structure of any dimensions, container modular buildings are somewhat limited to 20 foot and 8 foot increments.
The other considerations are building codes. The local building officials should be consulted early in the design portion of your project and involved throughout the process. It is their job to k now that you are constructing a safe building that meets all applicable building codes. Some of these codes may prove to be problematic in your design process. For instance, in most northern climates the International Building Code (IBC) as adopted by most states will require an R-19 insulation package in the exterior walls, this means you need 5 ½ » of fiberglass insulation plus ½ » sheathing or gypsum to accomplish the R 19 R value. Taking 6″ out of an 8 foot wide room can start to become a lot of valuable real estate when you consider standard mattress sizes and the distances you need to walk around the sides of your bed.
Another potentially problematic area is the height of standard shipping containers. Shipping containers have an exterior dimension of 8 feet and high cube containers are 9 foot 6 inches high. Once you calculate the required roof insulation package based on the local codes and a suitable covering you may lose up to 12 inches in your ceiling height bringing the finished ceiling height down to 7 feet above the finished floor. This may or may not be accepted by the local building official, if not you will need to purchase the more expensive « high cube » shipping containers in order to satisfy the energy code.
Shipping containers will make a great basis for a modular building project but you need to start the process understanding that you will have some tradeoffs to consider. You and your design professional will need to understand the building codes and have discussions with any building authority who will be inspecting and approving the final product.