Substitution Requests and the Or-Equal Clause

Picture a fictional spec that names three PLC manufacturers “or approved equal.” You have a fourth in the shop, on your standards, with better pricing. So you build the panel package around it, mark the datasheets, and send it in. It comes back Rejected with one line: an unnamed product needed a separate written request. One review cycle gone, and the request you should have filed with the package now starts after it.

The or-equal clause is not an invitation to submit whatever meets the spec. It is a door with a procedure on it, and the procedure lives in Division 01.

Named manufacturers and the or-equal clause

Specs name products in a handful of patterns. The words are clues, not permission slips: the technical section, Division 01, procurement documents and conditions together decide the procedure.

Reference standard, performance, or description only. No manufacturer is named. A product may be evaluated against those requirements through the ordinary submittal process, unless another project document adds an approval or substitution step.

Several manufacturers named, no "or equal." This may be a closed list. Check the product and substitution articles before assuming either that every named product is acceptable without qualification or that an unnamed product can never be proposed.

Named manufacturer or manufacturers "or equal" / "or approved equal" / "or equivalent." The phrase may let you propose an unnamed product, but it is not approval by itself. The project documents identify the comparison standard, required evidence, decision-maker and timing.

Basis of design. Newer master specs name one product as the basis of design and let comparable products from listed manufacturers through the submittal process, while anything else is a substitution. Read the section's own article on comparable products; it says which.

One water utility spec I hold gives the contractor one proposed or-equal product of each type. If it is not accepted, the specified product goes in. That is one project's rule, not an industry default, but it is the or-equal clause with its teeth showing. Read yours before you build the package.

The Division 01 substitution procedure

MasterFormat puts it at 01 25 00 Substitution Procedures, with the product-naming rules next door in 01 60 00 Product Requirements. Older books put both in 01600 Material and Equipment or 01630 Product Substitution Procedures. Some books skip the separate section and put the procedure in the general conditions or in the instructions to bidders. Find it before you propose anything, because it defines four things:

1. What counts as a substitution. The common definition is any change in products, materials, equipment, or methods of construction from those required by the contract documents. Many books split it into substitution for cause (the specified product is unavailable, discontinued, or no longer meets code) and for convenience (you would rather supply something else), and treat the two very differently.
2. When a request may be filed. Covered below; it is the deciding factor.
3. What the request must contain. Also below.
4. How it is answered and what happens if it isn't. Typically the engineer either approves, approves as noted, rejects and directs the specified product, or returns it as too late. Some master specs set a window for the decision and state that silence means use the product specified.

Some general conditions distinguish an or-equal that requires no change in related work from a substitute that affects design or other work. Your contract may draw the line differently. A PLC that changes rack size, power budget or another trade's interface deserves the full procedure and coordination review rather than an assumption based on the words "or equal."

What to attach

A datasheet and a note make the reviewer do your comparison for you. That is a good way to spend a review cycle getting “more information required.” Build the request from the project's form and procedure. Common fields include:

• The form itself, one product per request, referencing the spec section and paragraph and the specified product by name.
• A point-by-point comparison of the proposed product against every requirement of the section's Part 2 and the specified product's salient characteristics. Same table, three columns: requirement, specified, proposed. This is the document the engineer actually reads.
• Product data for the proposed item, marked the same way any submittal is marked.
• The reason. Unavailability with a manufacturer's letter, a regulatory change, or, for convenience, the benefit to the owner: cost credit, schedule, maintenance. "We stock it" is not a reason an engineer can approve.
• Effect on other work: dimensions, clearances, power demand, wiring, other trades' drawings, and the cost of any redesign. At least one owner's section requires that revised drawings affected by the substitution be prepared and stamped by a professional engineer at the contractor's expense.
• Cost and schedule impact, stated as a number and a date, including a credit if the substitute is cheaper. Some forms waive later claims for cost or time related to the substitution once it is accepted.
• Warranty, service, and parts equal to the specified product, with the local source named.
• Certifications the section demands, listing and agency marks included.
• Any signed certifications the project form requires, after the person authorized to make them has verified the comparison, coordination and stated impacts.

Attach what your procedure calls for the first time. The evaluation is a comparison, and you are the one who has to make that comparison possible.

Before bid versus after award

Timing is the variable that decides more substitution requests than merit does.

Before bid may offer a prior-approval window. The instructions to bidders state the deadline, evidence and effect of an addendum. If that path exists, using it can settle the product basis before pricing and package preparation.

After award may have a different, shorter window or may limit requests to stated causes such as unavailability. Read the actual deadline and trigger. A bid-stage prior approval and a post-award substitution request are different procedures even when they concern the same product.

The trap sits between the two. You bid with the fourth manufacturer in mind, meaning to sort it out later. "Later" is after award, when the request is for convenience, the window may already be shut, and the engineer's easiest answer is the named product. The reading of the spec section that finds the named-manufacturer list and files the prior approval request before bid is described in how to read a spec section for submittal requirements.

When it becomes an RFI

Not every question about a named product is a substitution. It is an RFI when the contract documents cannot be read to say what is required: a listed product line has been discontinued and the section was never updated, two paragraphs name conflicting products, the named model cannot do what Part 2 demands. Ask the question, cite both places, propose the answer. The engineer answers an RFI by clarifying or supplementing the documents, which is a different act from approving your choice.

Two rules keep the channels straight. An RFI is not the way to request approval of a substitution; at least one owner's RFI section says so explicitly and rejects RFIs used that way. And a discontinued product is handled as a substitution for cause with the manufacturer's letter attached, not as an RFI, unless the spec's own list is internally inconsistent. The broader judgment is in submittal versus RFI.

What a rejected substitution costs

The procedure exists because the downside is asymmetric. If the request is rejected, or never filed and the submittal is bounced for it:

• The named product may still be required. Check the consequence stated in the product and substitution clauses.
• Evaluation or redesign costs may be allocated to the requester. Include them only when the project documents say so.
• The extra review cycle can affect the order date. See sequencing submittals against lead times and use the actual project schedule.
• Early procurement can create exposure. Confirm acceptance and purchasing authority before ordering an unnamed product.

Against that, a prior approval request before bid starts with a form. The arithmetic is not close.

One fictional example

Section 40 61 13 Part 2 names three PLC platforms "or approved equal." The integrator's standard is a fourth. Two ways the job goes:

Same spec, same product, same integrator. The difference is a form filed in the right week.

How Submittal Kit handles this

Finding out from a Rejected stamp that your PLC was never on the list costs a review cycle. In Submittal Kit you link the submittal to its spec section and press Run spec check: every datasheet is read against the section's Part 2 and Part 3, and a manufacturer that is not on the section's list comes back as Does not meet, with a next action that says whether to swap the product or ask the engineer. Run it the week the package starts, while a substitution request can still go out on time. Rows that depend on the ordered configuration come back as Look at this instead of a guess, and you can mark any row yourself with a note that survives re-runs. The request form and its deadline still come from Division 01. See Spec check and RFI basics.

Disclosure: I build Submittal Kit, and no software changes the deadline or approval path in your project documents.