Prefab Sourcing for US Projects: 7 Questions Buyers Actually Ask

I run quality and brand compliance at FrameGate Sourcing. I review every project package before it goes to a buyer — around 180 specs a year. In 2024 I rejected 14 first-article deliveries because panel fit was out of spec, finish didn't match the approved sample, or the connection detail on the drawing didn't match what was on the pallet. That's not a complaint. It's the job.

What follows is my attempt to answer the questions US buyers actually ask us — the ones that show up in every first call regardless of whether they're ordering a single leisure home or thirty volumetric modules. Short, direct, and honest about where my knowledge stops.

1. What does "total landed cost" actually mean — and why is it never the number on the quote?

Bottom line: the quote is FOB. The landed cost is everything between the factory gate and your site driveway.

When we help buyers compare total landed cost for US projects, we break it into these buckets:

• FOB product price (and what "FOB" actually covers — usually not crating or pre-ship photos)
• Ocean freight, plus the bunker and peak-season surcharges that show up after you've agreed a rate
• Duties and tariff classification — the HS code for a Panelized Prefabricated House is not the same as a knockdown kit, and the difference is real money
• Port fees, drayage, and last-mile trucking, which always cost more than the freight forwarder quoted
• On-site receiving — crane time if you need it, storage if you don't
• Contingency, usually 5-8% (things go wrong)

A ballpark rule we use: on a typical leisure home shipment to the US West Coast, landed cost runs 25-40% above FOB. Anyone who tells you it's 10% either forgot something or is hoping you won't notice until the invoice arrives.

2. How do I verify a factory's "code compliant" claim?

I'm not a code official, so I can't tell you whether a specific panel spec meets the IRC as adopted by your county. What I can tell you from a quality and compliance perspective is how to read what the factory is handing you.

"Code compliant" is not one claim. It's usually one of these three:

• "We build to standard X." Ask which standard, then ask for the certificate showing the factory was audited against it. If there's no certificate, it's marketing.
• "We're ICC-ES evaluated." Ask for the actual ESR number. Look it up. It tells you exactly what was evaluated — often a specific panel assembly, not the whole house.
• "We're HUD-compliant." That only applies if the unit is literally manufactured housing under the HUD code. A modular home built to IRC isn't the same animal. Don't let the two get confused on a quote sheet.

From the outside, a supplier with a wall of certifications looks more qualified. The reality is that half of those certificates cover materials the supplier buys, not assemblies the supplier makes. Ask what the certificate covers before you file it.

3. We're only ordering three or four units. Will we get treated like an afterthought?

Here's where I'll take a position: small orders shouldn't be awkward to place. Ever.

When we were starting out, the two vendors who took our three-unit test order seriously — who sent pre-ship photos without being asked, who flagged that a door frame spec would fail our local inspector, who didn't push us into a twenty-unit minimum just to make their paperwork easier — are still the ones we buy from today at ten times the volume. The vendors who told us to "come back when you're serious" are not.

Real talk on what to expect: your per-unit price will be higher. That's not discrimination, it's manufacturing math. Container fill, setup time, and inspection all spread across a smaller number of units. A fair small order isn't a small order at a large-order price — it's a small order at a small-order price, with large-order service.

The red flag isn't a minimum order quantity. It's a supplier who won't give you an hour of engineering attention before they have your money. Trust me on this one — that's not going to improve after the wire clears.

4. How do we shortlist manufacturers without flying to Asia?

You don't need a factory visit to filter the field. You need three things from each candidate:

1. A redacted reference project in the US. Same product category, same climate, same code jurisdiction if possible. Then call the buyer. If the factory won't connect you, that's a data point.
2. An RFQ response that answers the questions you asked. Watch for suppliers who quote on a different product than you specified, or who return a price without a spec breakdown. Both are stealth ways of saying "we're going to substitute something."
3. A third-party pre-shipment inspection. Budget for it early. An inspection you schedule yourself, with an inspector who doesn't work for the factory, is worth more than every glossy brochure in the folder.

People assume the supplier labeled "audited" is safer. What they don't see is who commissioned the audit and what the scope actually covered. A social compliance audit from a brand customer doesn't include dimensional checks on your panels.

5. Why are two quotes for the same panelized prefab sixty thousand dollars apart?

People think the lower quote reflects a leaner factory. Usually it reflects a factory that deferred a cost you haven't found yet.

The causation runs closer to the opposite of what buyers assume. Vendors who deliver quality can charge more — not the other way around. Some of the gap is real efficiency. Most of it is scope.

Before you compare the numbers, line up these five line items side by side:

• Wall and roof panel thickness, with actual R-values, not adjectives
• Window and door spec — including who supplies the glazing and whether it meets your local energy code
• Connection hardware (bolts, plates, brackets): included or "by others"
• Electrical and plumbing rough-in: inside scope or explicitly excluded
• Packing method (flat rack, open top, or standard container) and what happens to damaged panels

If a twenty-percent gap survives that comparison, that's a real gap. If it collapses, the low quote was a story.

6. What's the biggest thing buyers forget to put in their RFQ?

Tolerances and drawing conventions. Almost every time.

Buyers write a spec sheet and assume it's self-explanatory. It isn't. Two things I ask every buyer to add before we push an RFQ out to factories:

• Dimensional tolerances — panel length tolerance, squareability, wall plumb. If you leave it blank, the factory will pick one that's very forgiving to them and barely workable on your site.
• Which drawing standard — ISO, ANSI, or the factory's own. If you don't specify, you'll get the factory's, and your local inspector may not recognize it.

This is the boring, unglamorous part of sourcing alternative products. It's also the part that keeps your project from a two-week site delay and a rewrite of the connection detail on port arrival.

7. Is a "90-day lead time" realistic?

Honestly, I've never fully understood why the same scope comes back at 45 days from one factory and 95 from another. Some of it is production capacity. Some is buffer — what the sales team adds so they don't have to apologize later. My best guess for the rest is that some factories schedule against confirmed POs while others only start the clock after the deposit clears and the drawing sign-off is back in writing.

What I can tell you from a compliance perspective: the only lead time that means anything is the one in the contract, tied to a signed drawing package and a defined start date. An email that says "typically 90 days" is not a lead time. It's a wish.

If you want a number you can plan a project around, ask for the contract language first, then negotiate the number. Not the other way around.