# Or-Equal vs Substitution Request: Key Differences

> Source: https://deviationcheck.com/guides/or-equal-vs-substitution/

Or-equal and substitution sound interchangeable, and that confusion costs real money. A sub submits a product the spec never named, calls it an "or-equal," and skips the form the contract actually requires - so the architect never sees it, the wrong material gets installed, and someone eats a backcharge. Knowing which path a submittal is on tells you exactly what to check and who has to sign off.

## What "or equal" actually means

An [or-equal](/glossary/or-equal/) provision lives inside the spec itself. When a section names a product "Acme Model 400 or equal," the spec is telling you up front that other products are acceptable, as long as they match the performance and quality of the named one. The named product sets the bar. That bar is usually called the [basis of design](/glossary/basis-of-design/) - the specific model the engineer drew, sized, and detailed around.

The sub is not asking permission to use a different category of product. They are claiming their product meets the **salient characteristics** of what the spec already allows. Salient characteristics are the measurable requirements that matter: dimensions, load rating, fire rating, finish, ASTM standards, electrical ratings, warranty length. If the spec says 1-hour fire rating and 0.032 aluminum, an or-equal product has to hit both, on paper, before anyone calls it equal.

The catch: "or equal" is not "or whatever is close." The burden sits on the sub to prove equality, and on you (and often the design team) to agree. A spec written as a [proprietary specification](/glossary/proprietary-specification/) - one named product, no "or equal" language - gives the sub no opening at all. Read the spec language before you assume an or-equal path even exists.

## What a substitution request is

A [substitution request](/glossary/substitution-request/) is a formal ask to use something the spec did NOT pre-approve. The sub wants a different manufacturer, a different system, or a different method than what the documents call for, and the spec gives them no "or equal" door to walk through. So they have to ask, in writing, on a real form.

Most projects spell this out in Division 01 (often Section 01 25 00, Substitution Procedures). The contract sets a deadline - commonly substitutions must be submitted within 30 days after the notice to proceed, or before bid in some delivery methods. After that window, the answer is usually no unless a named product gets discontinued or a genuine problem surfaces.

A substitution request rides on a substitution request form, and that form does work. It asks the sub to state why they want the change, what the cost difference is (a credit or an add), what the schedule impact is, and how the proposed item compares point by point to the specified one. The [architect of record](/glossary/architect-of-record/) reviews it and either approves, approves as noted, or rejects. Until that signed approval comes back, the specified product is still the contract requirement. No approval, no substitution.

## The key differences

| | Or-equal | Substitution request |
|---|---|---|
| Who initiates | Sub, when submitting | Sub, by formal request |
| When allowed | Anytime - the spec already permits it | Only inside the contract's substitution window |
| Approval required | Confirm it meets salient characteristics; design team often concurs | Architect/engineer of record must formally approve |
| Documentation | Submittal data showing equality | Substitution form, side-by-side comparison, cost and schedule data |
| Timing pressure | Low - part of normal submittal flow | High - misses the deadline, gets rejected |

The short version: an or-equal is the sub using a door the spec built for them. A substitution request is the sub asking you to cut a new door.

## How a PM should handle an or-equal claim

Start with the spec, not the submittal. Open the section and confirm it actually says "or equal" (or "approved equal"). If it does not, the sub does not have an or-equal claim - they have an unfiled substitution, and you should send it back on that basis.

Then check the proof:

- **Salient characteristics.** List the requirements the spec calls out - ratings, dimensions, standards, finish, warranty. Match the sub's cut sheet against each one. A missing line is a deviation, not a rounding error.
- **Basis of design.** Compare the proposed product to the named product side by side. If the engineer sized ductwork, conduit, or structure around the basis-of-design unit, an "equal" that draws more power or weighs more is not actually equal.
- **Signed approval.** Many contracts still route or-equal determinations through the design team. Get the architect's or engineer's concurrence in writing before you stamp it. Your stamp alone may not cover you if it fails later.

If the data is thin, mark it Revise and Resubmit and tell the sub exactly which characteristic is unproven. Vague rejections come back as the same vague submittal.

## How a PM should handle a substitution request

Treat the form as the gate. Before the request goes to the design team, confirm it is complete and timely:

- **Form completeness.** Every field filled - reason for the request, full product data, and the point-by-point comparison to the specified item. An incomplete form is not a real request.
- **Deadline.** Check it against the Division 01 substitution window. Past the cutoff, the default answer is no, and you can say so without involving the architect.
- **AOR approval.** Route the complete request to the architect or engineer of record. They own the yes or no. Do not let a sub start procurement on a "verbal okay."
- **Cost and credit.** Pin down the dollar impact in writing. If the substitution is cheaper, the owner is usually owed the credit. If it adds cost, settle who pays before anyone proceeds.
- **Schedule impact.** Get the lead-time difference on paper. A substitution that "saves money" but adds four weeks to a critical-path delivery is not a deal - it is a delay claim waiting to happen.

For the deeper workflow around stamping, logging, and returning submittals, see the companion guide on [how to review a construction submittal](/guides/how-to-review-a-submittal/).

## Common mistakes

- **Treating a silent swap as an approved or-equal.** The sub ships a different brand, never flags it, and assumes "or equal" covers them. It does not. An unproven, unstated swap is a deviation - catch it against the basis of design before it gets installed. The manufacturer-substitution patterns in [Manufacturer or Product Substitution in Division 09 Finishes](/divisions/09-finishes/manufacturer-substitution/) and the same category for [Division 26 Electrical](/divisions/26-electrical/manufacturer-substitution/) show what these look like in real packages.
- **Letting a substitution ride in as an or-equal.** When the spec has no "or equal" language, a different product is a substitution and needs the form, the deadline, and the AOR sign-off. Do not let the easier label skip the harder process.
- **Stamping an or-equal without checking salient characteristics.** "Looks about the same" is not a review. If you did not match every called-out rating and dimension, you did not confirm equality.
- **Missing the substitution deadline and approving anyway.** Once the Division 01 window closes, an out-of-time substitution is grounds for rejection. Approving it informally waives a protection the contract gave the owner.
- **Skipping the cost and schedule columns.** Approve the product, forget the credit and the lead time, and you have handed the sub a free change and a possible delay. Both belong in writing before procurement starts.

When a package lands and you are not sure which path it is on, you can [start a review](/#pricing) and get the deviations flagged against the spec before they reach the field.

## Frequently asked questions

### Does an or-equal product need architect approval?

Often yes. Even though the spec permits equals, most contracts route the equality determination through the architect or engineer of record, and a written concurrence protects you if the product later fails.

### What happens if a sub misses the substitution deadline?

The default answer is rejection. Division 01 usually sets a window (commonly 30 days after notice to proceed), and once it closes you can reject an out-of-time substitution without sending it to the design team, unless a specified product was discontinued.

### Can a sub use any product if the spec does not say "or equal"?

No. A spec with one named product and no "or equal" language is a proprietary specification. Any other product is a substitution that requires the formal form, the deadline, and architect or engineer approval before it is allowed.