Product selection and substitutions · Lesson 1 of 4

Product selection and substitutions: principles and terminology

Why a small product change is rarely small, where the substitution rules live in a project manual, how a specification selects a product, the difference between a comparable product and a substitution, and who decides.

You will be able to: Define selection procedure, basis-of-design product, comparable product, substitution and code alternative, say which procedure a given specification wording triggers, and name who decides.

12 min · 12 slides · 9 questions

All lessons in this module

Slide 1 of 12

A small change is rarely small

An IIBEC article by staff of an edge-metal manufacturer says edge systems are frequently value engineered out of a project or replaced with shop-bent, untested products.

The same article names lighter-gauge material from value engineering as a primary reason for roof failures.

Swapping a product is a design decision with consequences. The rest of this module gives the words and the method.

Sources

Specifying to reduce risk and improve performance of perimeter edge metal systems (IIBEC Interface, December 2019) - IIBEC; article by staff of OMG Roofing Products, a manufacturer

Glossary

Basis-of-design product: A specification names one manufacturer’s product, marked as the basis of design, to set the qualities used to judge comparable products from other named manufacturers.
Comparable product: A product shown through the submittal process to equal or exceed the specified product in type, function, dimension, performance, physical properties and appearance.
Substitution: The contractor proposes a different product, material, equipment item or method than the Contract Documents call for.
Salient characteristics: The descriptive, performance and reference-standard requirements that define what a product must meet before it can be called equal.
Code alternative: A material or method the building code does not prescribe, approved by the building official when at least equivalent to the one prescribed.