| Structural design basis |
Local building code; applicable Eurocodes, International Building Code, or national structural code |
Load combinations, structural members, connections, foundations, serviceability, and regional design conditions |
Project-specific structural calculations, signed drawings, design assumptions, and engineer credentials where required |
Calculations should identify the exact site, building use, number of floors, design life, and governing load cases |
Site-specific |
| Wind resistance |
Local wind code; ASCE 7, EN 1991-1-4, or equivalent national standard |
Basic wind speed, exposure category, pressure coefficients, uplift, racking, anchorage, and cladding performance |
Wind-speed basis, pressure calculations, connection details, anchor layout, and wind-test reports when available |
Do not compare a single generic wind number; compare the complete design basis and the tested or calculated load path |
Site-specific |
| Snow and roof loading |
Local snow-load code; EN 1991-1-3, ASCE 7, or equivalent |
Ground snow, roof snow, drifting, unbalanced loading, rain-on-snow effects, and roof drainage |
Roof-load calculations, member sizes, deflection checks, drainage details, and site elevation assumptions |
The stated snow capacity must be tied to a recognized code and the actual project location |
Site-specific |
| Steel material and fabrication |
EN 1090 where applicable; ASTM, JIS, GB, or another accepted material and fabrication specification |
Steel grades, welding procedures, fabrication tolerances, traceability, factory production control, and execution quality |
Mill certificates, welding procedure specifications, welder qualifications, inspection records, and coating reports |
Material certificates should identify the grade, heat or batch number, test results, and connection to the supplied frame |
Required where specified |
| Welded and bolted connections |
Applicable structural steel code; ISO 3834, AWS D1.1, EN 1090, or local equivalent where relevant |
Weld quality, bolt grade, torque or tension, connection capacity, fatigue considerations, and inspection level |
WPS/PQR records, welder qualifications, bolt certificates, torque records, visual inspection, and non-destructive testing reports |
Critical load-path connections should have documented inspection rather than visual claims alone |
Required where specified |
| Container geometry and corner fittings |
ISO 668, ISO 1161, and ISO 1496-1 when the unit is marketed or handled as an ISO freight container |
External dimensions, corner fittings, stacking-related requirements, handling loads, and container testing principles |
Dimensional inspection, corner-fitting certificates, handling instructions, and test documentation |
A folding accommodation unit should not be assumed to be a certified freight container unless the relevant ISO requirements are actually demonstrated |
When applicable |
| Foundation and anchorage |
Local foundation and geotechnical requirements; applicable seismic and wind codes |
Soil bearing capacity, settlement, uplift, sliding, overturning, anchor bolts, and temporary or permanent support conditions |
Foundation plan, anchor details, soil assumptions or geotechnical report, and installation tolerances |
The supplier should state whether foundations are included and identify who is responsible for final foundation design |
Site-specific |
| Seismic performance |
Local seismic code; ASCE 7, EN 1998, or equivalent national standard |
Seismic design category, ductility, diaphragm action, bracing, connection detailing, and anchorage |
Seismic design calculations, bracing drawings, connection details, and engineer review |
“Earthquake resistant” should be supported by a project-specific seismic design basis, not only a product brochure |
Site-specific |
| Fire resistance of assemblies |
ASTM E119, EN 1363/EN 1364, or the fire-test method required by the destination code |
Fire-resistance ratings for walls, floors, roofs, doors, penetrations, and structural protection systems |
Test report or classification report for the complete assembly, including thicknesses, joints, and penetrations |
Check the tested assembly, not just the fire rating of an individual panel or insulation material |
Code-dependent |
| Reaction to fire and insulation |
EN 13501-1, ASTM E84, or the destination market’s required classification method |
Flame spread, smoke development, combustibility classification, thermal insulation, and condensation control |
Product test reports, classification documents, technical data sheets, and installation limitations |
Compare the full wall or roof build-up and verify that the tested product matches the installed product |
Code-dependent |
| Electrical safety |
IEC 60364, NFPA 70 (NEC), or the destination country’s electrical installation code |
Protective earthing, overcurrent protection, residual-current protection, cable sizing, routing, outlets, and wet-area safety |
Single-line diagram, circuit schedule, component certificates, continuity tests, insulation-resistance tests, and electrical inspection record |
Electrical work should be reviewed or certified by a qualified person accepted in the destination jurisdiction |
Jurisdiction-dependent |
| Plumbing and sanitation |
Local plumbing code; applicable ISO, EN, ASME, or national product standards |
Potable-water materials, drainage, venting, backflow prevention, pressure testing, and sanitary fixtures |
Pipe and fitting approvals, pressure-test results, drainage layout, fixture specifications, and commissioning checklist |
Confirm compatibility with local water pressure, drainage connections, climate, and wastewater requirements |
Jurisdiction-dependent |
| Thermal performance and energy efficiency |
Local energy code; ISO 6946, EN ISO 10211, or equivalent calculation method |
U-values, thermal bridges, air leakage, vapor control, condensation risk, windows, and HVAC efficiency |
Whole-envelope U-value calculations, thermal-bridge details, air-sealing specification, and HVAC data |
Compare complete wall, floor, roof, and window assemblies rather than insulation thickness alone |
Climate and code dependent |
| Water tightness and weather resistance |
Applicable facade, roof, window, and door water-penetration tests required by the destination code |
Roof joints, folding seams, flashing, sealants, windows, doors, drainage paths, and repeatable opening cycles |
Water-penetration test reports, joint details, sealant specifications, and installation instructions |
Request details for every folding joint and verify that seals can be replaced after transport and installation |
Required for occupied use |
| Corrosion protection |
ISO 12944 or an equivalent coating and corrosion-protection specification |
Environmental corrosivity category, surface preparation, coating system, dry-film thickness, and repair procedure |
Coating specification, surface-preparation record, dry-film thickness readings, and touch-up instructions |
The coating system should match the site environment, especially coastal, industrial, humid, or de-icing-salt exposure |
Environment-specific |
| Manufacturing quality management |
ISO 9001 certification or an equivalent documented quality-management system |
Document control, purchasing, production checks, nonconformance handling, corrective action, and traceability |
Valid certificate, certification scope, issuing certification body, audit status, and inspection-and-test plan |
Verify that the certificate scope covers the relevant construction or fabrication activity; ISO 9001 does not certify building safety by itself |
Strongly recommended |
| Occupational health and safety |
ISO 45001 certification or an equivalent occupational health and safety system |
Factory safety processes, hazard controls, worker training, incident management, and continual improvement |
Valid certificate, scope, audit status, and site safety procedures |
Use it as a supplier-management indicator, not as a substitute for structural, fire, or electrical compliance |
Strongly recommended |
| Environmental management |
ISO 14001 certification or equivalent environmental-management system |
Waste, emissions, chemical handling, environmental objectives, and compliance controls |
Valid certificate, scope, environmental policy, and relevant compliance records |
Helpful for procurement screening, but it does not prove product performance or building-code compliance |
Procurement criterion |
| Product and project certification |
Destination-market product approvals, local authority approval, or third-party listing where required |
Whether the exact model, configuration, materials, and intended use are accepted in the target jurisdiction |
Certificate number, issuing body, scope, validity, model reference, limitations, and installation conditions |
Check the certificate against the exact supplied model; a certificate for another product or factory is not sufficient |
Market-specific |
| Factory inspection and pre-shipment control |
Contract inspection plan; ISO 2859-1 sampling may be used for selected inspections |
Dimensions, folding mechanism, fasteners, doors, windows, finishes, appliances, packing, and visible defects |
Approved drawings, inspection checklist, photographs, test records, serial or batch traceability, and packing list |
Use an agreed hold point before shipment and record deviations against approved drawings |
Recommended for every order |
| Installation, operation, and maintenance |
Manufacturer instructions plus local construction, lifting, electrical, and workplace-safety requirements |
Unfolding sequence, lifting points, temporary bracing, anchoring, utility connection, inspection, and maintenance intervals |
Installation manual, lifting plan, torque values, replacement-seal list, warranty terms, and training records |
Reject designs that rely on undocumented field modifications or provide no procedure for inspecting folding joints |
Required for safe use |
