The Building Code applies the same requirements to site-built and factory-constructed buildings. However, it can often be difficult to determine whether a factory-constructed building complies with the Code once it has been delivered to the construction site because many of the wall, roof and floor assemblies are closed in and so their components cannot be inspected. CSA A277, “Procedure for certification of prefabricated buildings, modules, and panels,” was developed to address this problem with regard to residential, commercial and industrial buildings. This standard describes a procedure whereby an independent certification agency can review the quality control procedures of a factory and make periodic unannounced inspections of its products. The standard is not a building code, only a procedure for certifying compliance of factory-constructed components with a building code or other standard. If a factory-constructed building bears the label of an accredited certification agency indicating that compliance with the Building Code has been certified using the CSA A277 procedure, the accepting authority will have some assurance that the concealed components do not require re-inspection on site.
On the other hand, standards in the CSA Z240 MH Series, “Manufactured homes,” do resemble a building code. Most of the individual standards in the series contain requirements regarding many issues also covered in the Building Code. Some of these Z240 MH Series provisions are performance requirements with no quantitative criteria, some simply reference the applicable Building Code requirements, while others contain requirements that differ from those in the Building Code.
Because it would be illogical to have two different sets of requirements for buildings—one set that applies to site-built buildings and one set that applies to factory-constructed buildings—the Building Code does not reference these Z240 MH Series standards. One of the individual standards in the Z240 MH Series deals with special requirements for manufactured homes related to the fact that these houses must be moved over roads, which is an issue the Building Code does not address.
Therefore, labeling that indicates that a factory-constructed house complies with the Z240 MH Series standards cannot be taken as an indication that the house necessarily complies with the building code in effect for the location where the house will be sited.
The Building Code does reference CSA Z240.10.1, “Site preparation, foundation, and installation of buildings,” which is not actually part of the CSA Z240 MH Series. This standard contains requirements for surface foundations where buildings—not just houses—comply with the deformation resistance test provided in CSA Z240.2.1, “Structural requirements for manufactured homes.”