Draft Details

Designation:CSA Z251
Source:CSA
Review start date:Feb 12, 2026
Review end date:Mar 14, 2026
Contact email:kristina.veri(at)csagroup.org
Draft Scope/Description:

1.1 Inclusions

This Standard specifies technical requirements for new buildings with the use of permanently installed volumetric modules, including

a)    structural design, including design for transportation, storage, and installation;

b)   building services;

c)    environmental separation;

d)   fire protection;

e)    energy efficiency design considerations;

f)    manufacturing; and

g)    architectural considerations.

1.2 Applicability

This Standard

a)    provides requirements and guidance for the design and construction of volumetric modular buildings other than those indicated in Clause 1.3; and

b)   supplements the building design and construction requirements in the codes applicable in the final installation location of the modular building.

1.3 Exclusions

This Standard does not apply to

a)    one-storey manufactured homes; and

b)   relocatable buildings.

Note: One-storey manufactured homes are covered by the CSA Z240 MH Series of Standards. Relocatable buildings are covered by UL 2600.

1.4 Terminology

In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.

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