What “or approved equal” means in a construction spec (and why manufacturers should care)

Read enough construction specifications and one phrase keeps coming back: “or approved equal.” It usually sits right after a named product, as in “TPO membrane, 60-mil: Manufacturer A, Product X, or approved equal.” For an architect it is a hedge. For a building-product manufacturer it is the difference between a project you can still win and one that is already written for someone else.

What “or approved equal” means

“Or approved equal” means the named product is the reference, not the requirement. A contractor may supply a different product if the design professional (usually the architect or engineer of record) agrees it meets the same performance, quality and appearance. The key word is approved: equality is decided by the design team, through the procedure the spec sets out, not by the contractor on their own.

You will also see the shorter “or equal” and the variant “or equal as approved by the Architect.” They work the same way in practice: a door is open, and the spec tells you how to walk through it.

Three ways a spec names products

Most product sections use one of three patterns, and telling them apart is the first thing a spec rep learns:

• Basis of design. One product is named as the one the design was built around. Others may be allowed if they match it. The basis-of-design manufacturer has the strongest position, but not a lock.
• Listed manufacturers. The spec names two, three or more acceptable manufacturers. If you are on the list, you can bid. If you are not, you need a substitution, or an addendum that adds you.
• Proprietary (no substitutions). Only the named product is acceptable. This is the closed door, and on publicly funded work it is generally the exception, because public owners are usually expected to keep bidding competitive.

“Or approved equal” can attach to either of the first two. When it does, the project is still winnable by a manufacturer who is not named.

Where to find it in a spec book

Specs written in CSI format split every section into three parts: Part 1 General, Part 2 Products and Part 3 Execution. Product names live in Part 2, usually in an article called “Manufacturers.” That is where you read who is basis of design, who is listed, and whether equals are allowed.

The rules for how to propose an equal live elsewhere, in Division 01. Look for 01 25 00 Substitution Procedures and 01 60 00 Product Requirements, plus the instructions to bidders. They set the deadline, the paperwork and who decides. See our MasterFormat guide for the section numbers that matter most.

How a substitution request works

The details vary by project, so always read the project’s own Division 01, but the shape is usually the same:

• Timing. Many public projects only consider substitutions before bid, through a prior-approval request due a set number of days before the bid date. After that window closes, the named products are what gets bid.
• Evidence. The request typically includes product data, a side-by-side comparison against the named product, test reports or listings, and warranty terms.
• Decision. The architect or engineer reviews it. Accepted products are often announced to every bidder in an addendum, which is why addenda are worth reading as closely as the original spec.

Why it matters to manufacturers

For a manufacturer, every “or approved equal” is a dated sales opportunity: a named competitor, a deadline and an architect to talk to. The teams that win are the ones that see it while the window is still open:

• Find out which open projects name a competitor and still allow equals.
• Note the substitution deadline, not just the bid date.
• Prepare the comparison the spec asks for, and send it to the architect early.
• Watch the addenda, where approved equals and product changes get published.