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Extracted Content

(This appendix is not part of this guideline. It is merely informative and does not contain requirements necessary for conformance to the guideline.)

INFORMATIVE APPENDIX K BASIS OF DESIGN

This appendix provides an example of how to implement part of Guideline 0. It is not intended to be a comprehensive representation or a best-practice example. Practitioners applying the Cx should carefully follow Guideline 0 and applicable commissioning technical guidelines tailored to their specific projects.

The BoD records the major thought processes and assumptions behind design decisions made to meet the OPR. The OPR is intended to capture what the Owner needs and expects from a project. The construction documents detail how the OPR will be physically achieved. The BoD captures important information linking the what and how .

BoD documentation is distinct from the construction documents, is seldom included in drawings and specifications, and is generally not needed by the contractor to meet his/her obligations. It is exceptionally valuable to the CxP Team, however, when evaluating the ability of a design and its components to meet the OPR.

The objective of specifically documenting BoD information is to provide the parties involved with a project, at each phase in the process, an understanding of the underlying thinking that led to the selection of specific components,

assemblies, systems, and system integrations. A design narrative that provides an overview of assemblies and systems in verbal format is usually an integral element of the BoD.

The BoD will typically be developed incrementally as work on a project moves from Predesign, to Design, and into the Construction Phase. Changes to the BoD that often occur as a design evolves must be documented.

The BoD will vary from project to project and system to system, but in general it should address the following:

a. Specific codes, standards, and guidelines considered

during design of the facility and designer interpretations of such requirements b. Information regarding ambient conditions (climatic, geo logic, structural, existing construction) used during design. c. Assumptions regarding use of the facility d. Expectations regarding system O&M e. Performance criteria that the system was designed to

meet, linked to the OPR f. Specific design methods, techniques, and software used in design g. A narrative statement of design that describes how the

designer intends to meet the OPR h. A narrative statement of operation that details how the

facility is expected to operate under various situations (such as normal operation, extreme event, emergency) i. A listing of specific manufacturer makes and models used as the basis for drawings and specifications

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