Prefab Dome Supplier Due Diligence Checklist: The Questions to Ask Before You Commit

A prefab dome supplier due diligence checklist is the set of questions a buyer should ask any dome vendor — before pricing, before an RFQ, and before treating a headline number as real. It exists to do one thing: make two quotes comparable on the same basis. Most buyer regret on a dome project does not come from picking the wrong geometry; it comes from comparing a shell-only price against a ready-to-move-in price, or accepting a certificate that does not transfer to the destination market.

This checklist is vendor-neutral on purpose. It works whether you are evaluating an EPS modular dome, a PVC fabric dome, or a geodesic kit, and whether the supplier is in China, Europe, or North America. Vaultwerk supplies the EPS modular Vaultwerk Dome Series, and the closing section shows how we answer each area — but the questions themselves are yours to ask everyone on your shortlist.

Request Quote — or work the checklist below first, then send the same questions to every vendor.

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The 30-second frame

If this checklist is forwarded to an owner, finance partner, or a project committee, the useful summary is this: a prefab dome is a long-lived asset bought on incomplete information, so the buyer’s job before an RFQ is to surface what each price actually covers and what each certificate actually proves.

Due-diligence area	The buyer’s core question	The failure it prevents
Product & structure	What is the envelope, and which standard was each rating tested to?	Buying a number (“B1”, “12-class wind”) with no test behind it.
Certification	Does each certificate transfer to my destination’s code?	A permit-stage rejection after the units have shipped.
Quote scope	Shell-only, ready-to-move-in, or turnkey — and what’s the Incoterm?	Comparing two prices that cover different things.
Track record	Can the supplier show real projects, packing, and documents?	Paying a deposit to a trader with no delivery evidence.
Logistics	Units per container, lead time, and who clears customs?	A landed cost and timeline that doubles the quote.
Site & install	Who does foundation, MEP, assembly, and waterproofing?	Discovering the “price” excluded everything local.
Multi-unit	Can units connect, and what’s the MOQ and batch logic?	A layout the system cannot actually build.

The rest of this guide unpacks each row into the exact questions to ask, why each matters, and the red flag that should slow a deal down.

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1. Product & structural facts

Before any rating means anything, find out what the envelope physically is and which test each headline number came from. A rating without a named standard is marketing, not engineering.

Ask:

• What is the envelope made of, and is it the structure, the insulation, or both?
• What fire rating does the material carry, and which standard was it tested to (GB 8624? EN 13501-1? ASTM E84?), as a component or as an assembly?
• What wind, snow, and seismic figures are quoted, and against which code or test reference?
• What insulation value (R-value, U-value, or W/m·K) does the wall carry, as a core material figure or as an installed assembly figure?
• How is service life described layer by layer — structural body versus coatings, sealants, and finishes?

Why it matters. Numbers like a fire class or a wind rating are only meaningful tied to the test that produced them, and a component test is not the same as an installed-assembly result. The buyer who records the standard next to each number can later hand it to a local engineer; the buyer who records only the number cannot.

Red flag. A supplier quotes “B1 fire-rated” or “12-class typhoon” with no standard, no test sheet, and no distinction between the material and the finished wall — or promises extreme-weather performance without pointing to a site-specific engineering review.

For how these questions resolve on an EPS envelope specifically — 18 cm module, GB 8624 versus EN 13501-1, and ASTM C578 R-value baselines — see the prefab dome house guide.

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2. Certification & destination compliance

International dome procurement is, underneath, a paperwork-mapping problem: the standard a product was tested to in its country of manufacture is almost never directly interchangeable with the standard your destination market requires for code compliance.

Ask:

• Which certificates do you hold (CE, SGS, GB 8624, others), and which exact standard and scope does each cover?
• Do you state in writing that these documents are an evidence base for my local consultant, not a substitute for destination approval?
• For my country, do you understand which destination tests apply — ASTM E84 / NFPA 285 (US), CSA A277 / ULC-S102 (Canada), EN 13501-1 (UK/Ireland), AS/NZS 3959 BAL (Australia)?
• Who, on my side, is expected to obtain the local permit and stamped engineering?

Why it matters. A Chinese GB 8624 four-class system (A, B1, B2, B3) has no one-to-one correspondence with the EN 13501-1 seven-class Euroclass system.¹ A CE mark is a European conformity mechanism; the US National Institute of Standards and Technology states it does not demonstrate compliance with North American safety standards or installation codes.² The mapping risk lands on the buyer at permit time, not on the supplier at quote time.

Red flag. A supplier equates a CE mark or a GB 8624 result with compliance in your market, or claims a single certificate “covers everywhere.”

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3. Quote scope clarity

Quote scope is the contract-level language that defines what is inside the supplier’s price and what you must arrange separately. Without it, two quotes cannot be compared, and the gap between stated price and operating cost stays hidden until the project is underway.

Ask:

• Is this price shell-only, ready-to-move-in, or turnkey — and what exactly sits in and out of each?
• What is the Incoterm (FOB, CIF, DAP)? Does the price include duties, port handling, inland freight, and installation?
• Is export reinforcement packaging a separate line item?
• What is the buyer-supplied items list — foundation, utilities, permits, local labour, tools, interiors, HVAC, FF&E?

Why it matters. A shell-only price from one supplier against a ready-to-move-in price from another creates a large apparent gap that disappears once scopes align — and that mismatch routinely distorts which supplier “won” the RFQ. Quote-scope parity, requiring every vendor to quote the same tier against the same buyer-supplied list, is the single highest-leverage due-diligence step.

Red flag. A single headline price, a per-square-metre rate, or a “dome kit” number with no tier and no exclusions named.

The full tier definitions and a paste-ready buyer-supplied items list are in the prefab dome house quote-scope chapter, and the lifecycle math behind why the cheapest day-one price is not always the cheapest asset is in the EPS vs PVC dome TCO guide.

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4. Manufacturing track record

You are buying delivery capability as much as a product. The goal here is to separate an accountable production-side supplier from a listing with no evidence behind it.

Ask:

• How long have you operated, and which production entity, export team, and named project contact stand behind the quote?
• Which markets have you exported to, and can you show real project photographs, container-loading evidence, and factory documentation?
• Can you provide references or case detail appropriate to my project size?
• What is stated in writing about warranty and after-sales, and who is the named project contact?

Why it matters. Real delivery leaves a trail — packing photos, certificates, project references. A supplier who can show that trail is materially lower-risk than one who can only show renderings. (A neutral note on evidence: concept renderings and stock images are legitimate marketing, but they are not delivery evidence — ask which images are real projects.)

Red flag. No verifiable project evidence, no clear answer on factory-versus-trader, or a deposit request before any documentation is shared.

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5. Logistics & lead time

The landed cost and the realistic timeline are where a clean unit price often doubles. Pull these forward before you sign, not after.

Ask:

• How many units fit in a 40-foot high-cube container for my chosen SKU, and how does that change for combined or larger footprints?
• What is the production lead time, and the shipping time to my destination port?
• Who is responsible for customs clearance, duties, port handling, and inland freight?
• What access constraints do you need to know — road width, crane access, lift height?

Why it matters. Container loading varies by footprint, packaging revision, and any export reinforcement framing, so a per-SKU container count is a quote input, not a fixed brochure number. Knowing it early lets you budget freight and duties as real line items instead of surprises.

Red flag. A supplier cannot give container counts or lead times, or quietly assumes you will absorb customs, duties, and inland freight that were never named.

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6. Site & installation

The shell is one layer; the building is many. Establish who owns each on-site responsibility before the units arrive.

Ask:

• What foundation does the system require, and who engineers and pours it?
• How are electrical, plumbing, and HVAC (MEP) routed, and who installs them?
• What is the assembly crew size, tool list, and supervisory support — and who provides each?
• What is the waterproofing and weather-sealing detail, and who is accountable for it on site?

Why it matters. Assembly time and site cost vary with crew, foundation prep, weather, and equipment; a “2-hour assembly” reference is a controlled-condition figure, not a site guarantee. Naming each responsibility owner is what turns a shell price into a project budget.

Red flag. Installation, foundation, and MEP are described as “easy” or “included” without a named owner, or waterproofing detail is left vague.

For the cold-climate end of the site envelope — thermal-bridge detailing, air-sealing at joints, and heating-cost framing — see the insulated dome house for cold climates guide.

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7. Multi-unit & project capability

For resorts, camps, and hotel groups, the unit is one component of a larger asset. The system has to support the layout the brief actually needs.

Ask:

• Can different unit sizes be physically connected into one building, or only placed adjacent?
• What is the minimum order quantity, and how does batch pricing work across unit-count tiers?
• What connection hardware, waterproofing, and structural detail apply at a junction, and is that quoted per project?
• What project-engineering support is available for a clustered or connected layout?

Why it matters. Connection capability separates a modular system that can build suites, family connectors, and shared cores from one that can only repeat identical standalone units — and it changes the long-tenure economics of a resort site. But connection detail is project-specific engineering, not a blanket promise, so it belongs in the quote.

Red flag. A supplier promises “any layout, any connection” with no per-project engineering, hardware, or waterproofing detail behind it.

For unit-count tiers, shared-space planning, and connection-node scope on a resort site, see the prefab dome house for glamping resorts guide.

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How Vaultwerk answers this checklist

This is a buyer’s tool, so the honest close is simply to show our side of it rather than market over it. Vaultwerk manufactures the EPS modular Vaultwerk Dome Series in China, and we structure our material to answer the seven areas above: factory documentation (a GB 8624 B1 fire report and an SGS RoHS / material-safety report; CE / EU DoC not claimed until verified) handed over as an evidence base for your local consultant, not as a destination-compliance guarantee; quotes structured by shell-only / ready-to-move-in / turnkey tier with a named buyer-supplied items list; container loading and lead time confirmed per quote against your destination port; and connection-node scope quoted per project for clustered layouts.

If you are running this checklist across a shortlist, send Vaultwerk the same questions you send everyone else.

• Share quantity, destination, intended use, and target scope through the inquiry form.
• Ask for the quote-scope tier breakdown and the buyer-supplied items list up front.
• Forward the Vaultwerk Evidence & Spec Brief internally — a one-page summary of the engineering record, certification references, SKU range, and quote-scope tiers.

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Related guides

• Prefab Dome House Guide (EPS specs, sizes, kits & quote scope) — what an EPS dome house is, what’s in the shell package, and the quote-scope language behind area 3. Published.
• EPS Dome vs PVC Dome Lifecycle Cost — the 10-year total-cost-of-ownership math behind “cheapest day-one price is not cheapest asset.” Published.
• Prefab Dome House for Glamping Resorts — unit-count tiers, shared-space planning, and connection-node scope for area 7. Published.
• Insulated Dome House for Cold Climates — thermal-envelope and heating-cost detail behind area 6. Published.

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Footnotes

1. CAS Fire, “GB 8624 and EN 13501-1 Comparison,” and RISE (Research Institutes of Sweden), “European Fire Classification.” There is no direct one-to-one correspondence between the GB 8624 four-class system and the EN 13501-1 seven-class Euroclass system. http://www.casfire.cn/en/?stm_event=gb-8624-and-en-13501-1 / https://www.ri.se/en/expertise-areas/expertises/european-fire-classification (accessed 2026-06-05). ↩

2. US National Institute of Standards and Technology (NIST), “Compliance FAQs: CE Marking.” CE marking is a European conformity mechanism and does not demonstrate compliance with North American safety standards or installation codes. https://www.nist.gov/standardsgov/compliance-faqs-ce-marking (accessed 2026-06-05). ↩