Modular Building Procurement FAQ: Comparing Supplier Options for Industrial Projects

I have priced, shortlisted, and walked away from more modular building suppliers than I would like to admit over the past six years — mostly sanitary facilities, project offices, classroom modules, and site-support units for industrial job sites. These are the questions I keep getting from colleagues who are new to the category, plus a couple I had to learn the hard way. Short version: no sales pitch, just answers.

1. When someone on my team writes "ATCO alternative" in an RFQ note, what are they actually asking for?

Usually it does not mean a knockoff. It is shorthand. When someone writes "ATCO alternative" or "ATCO-equivalent" in a procurement note, what they actually mean is: a modular building that meets the same functional spec as the reference unit we saw on a jobsite — same footprint, same finishes, roughly the same delivery window — but produced and supplied by a different company.

That is a descriptive use of the phrase, not an affiliation claim, and I make sure the RFQ says so explicitly. The comparison is on the spec, not the brand. In practice, the points that get compared side by side are:

• footprint and panel or skid dimensions
• wall, floor, and roof build-up with insulation R-value
• electrical configuration (voltage, phase, panel, service entry)
• sanitary fixture count and tie-in points
• delivery method: flat-packed, skid-mounted, or volumetric
• warranty terms and exclusions

If a supplier cannot produce a spec sheet that puts those items side by side, the alternative conversation is over before it starts. That sounds basic. It is also where half the shortlists fall apart.

2. How do I compare supplier options without running a formal tender?

For most of our modular purchases under a few hundred thousand dollars, we do not run a formal tender. We run a normalized three-quote comparison. That word normalized is doing most of the work.

I built the spreadsheet after getting burned in 2022 — two quotes that looked like a 14% gap turned out to be within 3% once I converted both to DDP terms and added the offload crane. That is the comparison that stuck with me. When I put the two quotes side by side, converted to the same basis, I finally understood why "unit price" is a useless number on its own.

The columns I actually use: unit price converted to DDP, freight to site, crane or offload, foundation and tie-in allowance, permit and inspection allowance on the buyer side, tax and duty, and any optional warranty extension. Three quotes, same columns, is usually enough to see who is genuinely competitive and who is just quoting a low number they know will not survive contact with the site.

3. What usually changes the total landed cost after the factory quote?

Site interface. Every single time.

Two years ago we priced a modular sanitary facility at $28,500 FOB from a factory — looked great against a local quote of $36,000. By the time it landed on our remote site it was closer to $34,200 once we added freight at $2,400, a crane rental we had not scoped at $1,800, a pad that turned out to be on us at $1,100, and a re-inspection after a labeling issue at $400. The "cheap" option ended up marginally cheaper than the local one, but the 25% gap we thought we had was mostly a comparison error, not a real saving.

"Includes delivery" can mean to the nearest port, curbside at the depot, or crane offload at the jobsite. Those are three different numbers and sometimes three different companies.

The lesson I have carried into every RFQ since: ask the factory what is and is not in the quote, in writing, line by line. The lowest unit price is often not the lowest total landed cost, and the buyer who does not normalize the two discovers this about six weeks after the unit arrives.

4. Does order size affect the quality of service you get?

It should not, and I push back when I see it happen.

I started in procurement on a small team. Our first modular unit was a single 20-foot sanitary building — maybe $8,000 to $9,000 total, give or take. Two suppliers told me they "do not really do one-off orders." One actually declined by quoting a number so inflated it was clearly a polite no. The other took the job, asked for a site address and a delivery window, and delivered on time.

Six years later, that second supplier handles around $150,000 a year of our unit purchases.

Small does not mean unimportant. It means early. A buyer on a single unit is testing the relationship — the delivery date, the paperwork, the punch list, the responsiveness when something goes wrong at 4 p.m. on a Friday. The pattern I have noticed across roughly 40+ modular orders is that the suppliers who take small jobs seriously are the same ones who take big jobs seriously. The ones who price to decline tend to price to decline on the big jobs too, just more politely.

That said — small orders do come at a different unit cost. That is manufacturing setup, not discrimination. What I object to is not the price. It is being treated as not worth a reply.

5. What actually derails these projects — because it is not the unit price.

People assume the risk in a modular building is the building. In our experience, the risk is the seam between the building and the site.

Three failure modes I have watched happen first-hand:

1. Utility tie-ins not scoped before the unit arrived — power, water, sanitary hookup.
2. Crane or truck access — a site road too narrow for the delivery vehicle, or a jobsite with no room for the offload.
3. Ground bearing capacity — an undersized pad, or a site that was graded after the quote was signed.

A modular sanitary unit, an office, a classroom — the unit itself is a controlled factory process. The site interface is the variable. When a project goes sideways, nine times out of ten it is because nobody wanted to own that seam, and the buyer (that is us) assumed "delivery" meant "installed" while the supplier assumed the opposite.

If you are pricing a project right now, write down who owns each line: the pad, the utility stub, the offload, the tie-in, and the final inspection. The code path should be on that list too, verified against your local AHJ before award — that is a buyer task, not something a supplier can sign off on. If any line is blank, that is your real budget risk. Not the unit price.

6. How should I structure an RFQ for a sanitary facility or site-support building?

Keep it to two pages or less. The factories we work with respond to clear spec sheets, not long narratives. I structure ours like this:

• Intent line: unit type, quantity, site ZIP, needed-in-service date
• Footprint and dimensional envelope, min and max
• Wall, floor, and roof build-up with insulation target
• Electrical: voltage, phase, service, panel location
• Plumbing: fixture count, tie-in point, whether we provide the connection
• Code path stated, with confirmation on the buyer side
• Delivery method and offload expectation, in writing
• Warranty terms and exclusions
• Payment milestones
• What we do not include, so it is on the record

On fixture count, a useful reference on the industrial side is OSHA 29 CFR 1926.51 for construction-site sanitation minimums — the count depends on headcount, shift overlap, and whether the facility is temporary or permanent. I put the reference in the RFQ and ask the supplier to spec to it. That is the buyer's job, not the factory's.

That last bullet — what we do not include — matters more than it looks. It is the sentence that prevents most disputes six weeks later.

7. What should I ask that most RFQs skip?

Two things.

First, the submittal and as-built package — before award, not after. I want to see the drawing set they will send for approval, the load calcs, and the fixture schedule. If a supplier cannot produce those before you sign, they will not have them when you actually need them.

Second, ask for the remedy in writing if the ship date slips. Not a promise — a remedy. What does the contract say happens if the unit misses the delivery window? Storage fees on your side, carry cost, a credit? Most factory quotes do not address this at all, which means the risk sits with the buyer by default. Making it explicit does two things: it forces the supplier to actually check their production schedule before committing, and it tells you whether they have thought about the answer before.

Neither of those questions gets asked in most RFQs I see. Both have saved us five figures over the years — not because suppliers failed, but because the ones who could answer well were easier to trust with a larger order.

Those are the questions I would want answered if I were starting this category fresh. If there is one I missed, I will probably hit it eventually — and I will come back and update this when I do.