Or Approved Equal: When to Bid and When to Walk Away
I watched an applications engineer spend most of a week on a package that his company was never going to win. He read the whole specification, priced the equipment, sized the motors and put together a proper submission.
Nobody had told him that a single line in the instructions, sitting nowhere near the technical sections, said substitute materials would not be permitted.
The manufacturer named in the specification had already won. Everything after that was decoration.
That week cost real money, and it was avoidable in about ten minutes of reading.
This article is about or approved equal, which is the three word phrase that decides whether a job is genuinely open to you.
Almost everything written about it online is written for the architect or the engineer who reviews substitution requests. This one is written from the other chair, for the manufacturer who has to decide whether to bid at all.
What the Phrase Actually Means
When an engineer writes a specification for a project, they usually have a particular product in mind. Often they wrote the section with that product's data sheet open in front of them.
So the specification will name it. Something like: "Fine bar screens, model FPFS-M, 304 stainless steel, by Duperon, or approved equal." That is a real line from a real public bid in Michigan.
The named product is called the basis of design. It is the one the engineer sized the whole system around. The words that follow it, "or approved equal", are supposed to keep the job competitive by letting other manufacturers offer something equivalent.
That is the theory. In practice the phrase can mean four completely different things, and telling them apart is the whole skill.
The Four Things Or Approved Equal Can Mean
One. You are the named manufacturer.
Good news, and also a warning. The bid is yours to lose, and your job changes from winning to defending. Somebody else is going to submit an equal, and how carefully you wrote your published specification months ago now decides whether that substitution succeeds.
Two. A competitor is named, and the door is genuinely open.
This is a real opportunity, and it is the situation most people underuse. The engineer had a product in mind, but the requirements are written around performance rather than around one company's part numbers. If your equipment meets them, you can compete on price and delivery.
Three. A competitor is named, and the door is shut without saying so.
This is the dangerous one, and it is the reason for this article. The words "or approved equal" are right there, but the requirements underneath them have been written so that only one product can possibly comply. I will come to the signals in a moment.
Four. The door is shut openly.
Some packages just say it. The Missouri bid I mentioned earlier contained the line "substitute materials or work shall not be permitted", and that was that. Rare, but it happens, and it is a gift when it does because at least it is honest.
How to Tell Which One You Are In
The difference between situation two and situation three is worth real money over a year, and you can usually work it out from the documents themselves. Here is what to look for.
Look for experience clauses first
This is the single most effective way to close a door while appearing open.
A public specification we read recently, for a water reclamation plant in Idaho, required that the manufacturer show at least ten installations of identically sized equipment with satisfactory performance. It sits in the quality assurance part of the section, several pages away from anything about materials or dimensions.
Read that carefully. Not ten installations. Ten installations of identically sized equipment. If your product line covers the size but you have delivered it eight times, you are out, regardless of how good the equipment is.
Variations you will see:
- A minimum number of years the product must have been in continuous service
- A requirement that installations be in the same state, or the same type of facility
- A requirement for references the reviewing engineer can call
- A minimum annual revenue or bonding capacity for the manufacturer
None of these are unreasonable on their own. Together they are often a wall.
Look at how specific the numbers are
Compare these two ways of asking for the same thing.
One: the unit shall remove ninety five percent of grit down to a stated particle size at the design flow.
Two: the upper chamber shall be a minimum of eight feet six inches in diameter, the chamber depth shall be four feet nine and a half inches, and the grit storage chamber shall be three feet two inches in diameter.
The first describes what the equipment has to achieve. Anybody who can achieve it can bid. The second describes one specific machine. Those dimensions came off a drawing of a product that already exists, and if yours is built differently you cannot comply no matter how well it performs.
Both of those come from the same real specification, in different sections. That is normal. The question is which style dominates the section that covers your scope.
Look for named model numbers inside the requirements
There is a difference between naming a manufacturer at the top of a list of acceptable products, and naming their part in the middle of a technical requirement.
The same Idaho specification listed four acceptable manufacturers for grit handling, then described the cone housing of one of them by its trademarked material name. When a proprietary product name shows up inside a paragraph describing how the thing must be built, the section was written around that product.
Look at the substitution procedure
Somewhere in the commercial documents there is usually a paragraph describing how to propose an equal. Read it before you decide anything, because it tells you how serious the invitation is.
Reasonable procedures ask for product data, a comparison against the specified item, and evidence of performance, usually a set number of days before the bid date.
Unreasonable ones ask for the substitution to be approved before bid, give you seven days to prepare it, require testing data from an independent laboratory, and state that the engineer's decision is final and will not be explained. That combination is a polite way of saying do not bother.
Look at who wrote the specification
If the same engineering firm writes most of the packages in your region, their habits matter more than any single document. Some firms genuinely run open specifications. Some write a basis of design and mean it. After a handful of packages you will know which is which, and that knowledge is worth more than anything in this article.
The Ten Minute Check
Before anybody starts pricing, somebody should answer these five questions. On a package of a few hundred pages this takes about ten minutes if you know where to look.
- Who is named, and where? In an acceptable manufacturers list, or inside the technical requirements themselves?
- Is there an experience clause? How many installations, of what size, over what period?
- Are the requirements about performance or about dimensions? Count roughly. Which style dominates your section?
- What does the substitution procedure ask for, and by when? Can you actually produce that in the time available?
- Is there a bid form alternate for your scope? If the owner has asked for two prices, they intend to choose, and the job is more open than the specification alone suggests.
If four of those five point the wrong way, walking away is a decision, not a failure. The week your engineer does not spend on that package is a week they spend on one you can win.
Why This Is Hard to Do Consistently
None of the above is complicated. It is just spread out.
The named manufacturers are in the product part of the technical section. The experience clause is in the quality assurance part, often several pages earlier.
The substitution procedure is in the commercial documents, in a completely different part of the book. The alternates are on the bid form, which most technical people never open.
To answer the five questions you have to read four different places and hold them in your head at the same time. That is why it usually does not happen. Not because estimators do not know it matters, but because the package arrives on Tuesday, it is due Friday, and there are two more behind it.
This is the part we automate. Our software reads the whole package and pulls out the named manufacturers, the experience clauses, the substitution procedure and the bid form alternates together, with the page number attached to each one. On a six hundred and sixty eight page book it takes under two minutes.
It does not decide whether to bid. That is your call, and it should be. It just puts the five answers on one screen before the week gets spent.
One Distinction Worth Learning
There is a case that looks like a locked door but is not, and I have seen it confuse people.
In a public package from New York, the floating dock decking was described as composite in one place and as treated pine in another. It looked like a contradiction, and a strict reading would have you asking the engineer which one they wanted.
They wanted both. The bid form carried composite and timber as separate priced alternates, because the owner intended to look at both numbers and choose. The specification was not confused at all. Somebody just needed to read the bid form.
In the same package, the gangway decking was described one way in the specification and a completely different way on the drawing sheet, with no alternate anywhere behind it. That one was a real problem and it needed a question asked.
The lesson is simple enough. A difference with an alternate behind it is a choice the owner is making. A difference with no alternate behind it is a question you have to ask. Treating them the same way either wastes the engineer's time or leaves you exposed.
What Mavlon Does
Mavlon is an AI quoting platform for engineer-to-order manufacturers. It reads the package your customer sends, in whatever form it arrives, and pulls out every requirement with the page it came from, including the parts of the or approved equal picture that sit in four different places.
There is a four minute walkthrough on a real public package here: Spec Says 48 Inches, Drawing Says 60.
Two related pieces:
- Using ChatGPT to Read Bid Packages: What Actually Breaks, on why a chat window struggles with documents like these
- Reading Bid Packages: What Five Real Ones Taught Us, where we counted what we found across five public packages
Want to know if a package is genuinely open to you? Send me a public bid and I will run it. Book a 30-minute demo.