Buying a modular house, capsule house, container home, or portable building from China starts with a quotation—but price is only the beginning of the project.
What determines whether a project is delivered successfully is the supplier’s real manufacturing capability, the transparency of its product specifications, the practicality of its drawings and shipping plan, and whether quality responsibilities are clearly defined in the contract.
CGCH works with expandable container houses, folding container homes, flat-pack container houses, capsule houses, and customized modular building projects. From our experience, buyers often focus first on appearance and price, while overlooking factory verification, material standards, waterproofing details, transport restrictions, and contract attachments.
This guide is designed for resort developers, glamping operators, hotel investors, contractors, distributors, and project buyers. Whether you eventually work with CGCH or another modular house manufacturer in China, these 15 checks should be completed before you make final payment.
AI Summary
Before purchasing a modular house from China, buyers should verify the supplier’s company registration, real factory capability, production process, material specifications, technical drawings, waterproofing details, export experience, shipping plan, inspection standards, and contractual responsibilities.
A reliable modular house manufacturer should provide transparent company information, real factory access, order-specific technical documents, clear quality-control procedures, and written acceptance standards. Price should not be the only deciding factor; buyers should compare suppliers based on product specifications, quality control, delivery capability, and contract responsibility.
First, Know Who You Are Buying From
A fast quotation does not necessarily mean a supplier has stable manufacturing and delivery capability.
In China’s modular construction industry, suppliers generally operate in one of three ways:
●A manufacturer with its own factory
●A trading company that coordinates several factories
●A sales company working with affiliated or partner factories
None of these models is automatically good or bad. What matters is whether you know who signs the contract, who receives payment, who manufactures the units, and who is responsible for delays, defects, and after-sales issues.
If the contract company, payment recipient, manufacturing factory, and export company are different entities, ask for a written explanation of their relationship and responsibilities before placing the order.
1. Verify the Chinese Company Name and Registration Number
Do not judge a supplier only by its English company name, website, brochure, social-media account, or Alibaba storefront.
Ask for the supplier’s Chinese business license and verify:
●The full Chinese legal company name
●The 18-digit Unified Social Credit Code
●The legal representative and registered address
●The company’s operating status
●The business scope, including steel structure, prefabricated buildings, container houses, or related manufacturing activities
●Any publicly listed business irregularities or legal risks
●The legal company name on the contract should match the name on the business license.
2. Confirm Who Is Responsible for the Order
Before you pay, ask clear questions:
●Who signs the sales contract?
●Who receives the payment?
●Who produces the modular house?
●Who handles export customs procedures?
●Who is responsible if the product is delayed, leaks, arrives with missing items, or does not match the agreed specifications?
A supplier saying “the factory will take care of it” is not enough. The responsible legal entity, warranty obligations, delivery commitments, and claim process should be stated in the contract.
3. Arrange a Live Factory Video Audit
Promotional videos, showroom photos, and finished sample houses are useful—but they do not prove current production capacity.
A more meaningful verification method is a live, continuous factory video call where the buyer can request specific areas to be shown.
Ask to see:
●The factory entrance, signage, and surrounding site
●Raw-material storage for steel, wall panels, insulation, windows, and glass
●Steel cutting, welding, grinding, coating, and assembly areas
●Units currently in production, not only display models
●Finished product storage and packing areas
●Container loading operations
●Electrical testing, plumbing work, waterproofing, or quality inspection points
For a modular building project, a showroom is not enough. Material processing, steel-frame fabrication, coating operations, assembly lines, finished-unit storage, and ready-to-ship units reveal much more about actual factory capability.
4. Understand Which Key Processes the Factory Controls
A modular house is not a single product. It is a combination of steel structure, wall systems, insulation, windows, glazing, plumbing, electrical systems, bathrooms, and interior finishes.
A supplier does not need to manufacture every component in-house. However, it should clearly explain which critical processes it controls directly.
Verify whether the factory manages:
●Steel-frame cutting, welding, and alignment
●Anti-corrosion treatment, painting, or coating
●Wall, roof, floor, and insulation installation
●Window, door, glass, and sealing work
●Electrical wiring, plumbing pre-installation, and equipment testing
●Final inspection, packaging, and container securing
The key question is not whether every part is self-produced. It is whether problems can be traced, corrected, and properly handled if something goes wrong.
5. Review Real Orders Similar to Your Project
A showroom unit may look excellent, but it does not always represent the quality of mass production or export delivery.
If you are sourcing capsule homes for a resort, glamping pods, worker accommodation, site offices, expandable container houses, or commercial modular units, ask to see real projects or current orders similar to yours.
Check whether the supplier has experience with similar:
●House size, layout, and interior configuration
●Project quantity and application
●Climate conditions, such as coastal, humid, hot, cold, windy, or snowy locations
●Shipping methods, including fully assembled, foldable, expandable, or flat-pack delivery
●On-site installation and lifting requirements
Different modular products require different buying decisions. Expandable container homes require attention to the expansion mechanism and transport efficiency. Flat-pack container houses are often suitable for camps, dormitories, offices, and larger site projects. Capsule houses and custom modular units require closer review of exterior cladding, glazing, waterproofing, interior fit-out, full-unit transport, and crane access.
6. Ask for Drawings and Specification Sheets, Not Only Renderings
A 3D rendering may show an attractive product, but it does not prove that the unit can be manufactured, transported, installed, or approved locally.
Before ordering, request technical documents that match your actual order, including:
●Floor plans, elevations, and key dimensions
●Structural and wall-system descriptions
●Window, glass, roof, floor, and insulation specifications
●Electrical and plumbing layout drawings
●Foundation connection details
●Finished dimensions, transport dimensions, unit weight, and lifting points
●A material and equipment schedule linked to the quotation
If the destination requires building permits, structural calculations, fire review, or professional certification, supplier drawings should be treated as design input. Local licensed professionals should confirm compliance with applicable regulations.
7. Specify Steel, Coating, and Connection Details
Terms such as “thicker steel,” “high-strength structure,” or “premium anti-rust paint” are not measurable acceptance standards.
Ask the supplier to specify the main structural material, section sizes, wall thickness, welding method, connection method, and coating system.
For coastal, high-humidity, high-salinity, high-wind, snowy, or high-temperature-difference locations, the standard product may not be sufficient. The steel structure, corrosion protection, drainage, insulation, and roof design should be reviewed according to the actual project environment.
Do not select a modular house from photos alone. Select it based on where and how it will be used.
8. Include Waterproof Testing in the Inspection Plan
For capsule houses and container homes, leaks often occur at details rather than large wall panels. Common risk areas include roof joints, glass edges, window frames, air-conditioner openings, exhaust openings, pipe penetrations, and floor connections.
Before production begins, confirm:
●Roof slope and drainage direction
●Roof-joint treatment and sealing method
●Window drainage design and glass finishing details
●Sealing methods for service penetrations and pipe connections
●Whether rain testing or water-spray testing can be completed before shipment
Waterproof testing, door and window operation, electrical testing, equipment operation, and drainage checks should be included in the pre-shipment inspection checklist.
9. Do Not Simply Ask, “Do You Have CE Certification?”
CE documents, ISO certificates, material test reports, management-system certificates, and local building permits are not the same thing.
One certificate does not automatically mean that a complete modular house complies with every country’s building regulations or every project requirement.
A better approach is to first identify:
●The country and city where the unit will be installed
●The intended use of the building
●Local permitting and compliance requirements
●Whether verification is needed for the structure, glass, electrical system, insulation, fire performance, or other specific components
Then check whether the certificate matches the actual manufacturer, product model, configuration, scope, and validity period.
10. Match Electrical and Plumbing Systems to Local Standards
Even when a prefab house is pre-installed in the factory, it still needs to connect to local electricity, water, drainage, and communication systems on site.
If voltage, plugs, power demand, water connections, or drainage locations are not confirmed in advance, costly site modifications may be required.
Confirm the following before production:
●Voltage, frequency, plug, and socket standards
●Distribution box, circuit breakers, residual-current protection, and grounding
●Total electrical load for air conditioning, water heaters, lighting, kitchen equipment, and appliances
●Water supply, drainage, wastewater, and ventilation connections
●Drainage protection for cold-weather conditions
●On-site connection requirements for local electricians and plumbers
11. Check Export and Container-Loading Evidence
A supplier saying it can export does not necessarily mean it has reliable international delivery experience.
Ask for recent, non-confidential evidence such as:
●Container-loading photos or videos
●Packing and securing plans
●Sample packing lists or commercial invoices
●Redacted bill of lading information
●Installation photos from destination projects
●Evidence of export packaging, moisture protection, and cargo securing
If the export entity is different from the manufacturer, ensure that the relationship and document responsibilities are clear before shipment.
12. Confirm Shipping Dimensions, Weight, and Lifting Conditions Early
A modular house may be able to leave the factory but still be unable to reach the project site.
Fully assembled capsule homes, large modular units, and oversized container houses may involve over-width, over-height, or overweight transport restrictions.
Before production, confirm in writing:
●Finished dimensions, transport dimensions, and total unit weight
●Whether standard containers or special containers are required
●Loading quantity per container and cargo-securing method
●Whether external components must be removed for transport
●Lifting points, crane capacity, and unloading requirements
●Road restrictions from the destination port to the project site
For mountain resorts, islands, scenic areas, remote locations, or sites with narrow roads, local logistics feasibility should be checked before manufacturing begins.
13. Link Payment Terms to Verifiable Milestones
A good payment arrangement is not only about the deposit percentage. It is about what must be completed before each payment is due.
The contract should define milestones for drawing approval, material confirmation, production progress, pre-shipment inspection, container loading, and final payment.
It should also state:
●The correction period for failed inspections
●Re-inspection arrangements
●Liability for late delivery
●Procedures for missing or non-compliant items
●How design or configuration changes will be handled
14. Use Third-Party Inspection for First Orders or Large Projects
For first-time cooperation, bulk purchases, high-value custom units, or project-based procurement, independent third-party inspection can significantly reduce risk.
Inspection should be based on the agreed contract, drawings, and specification sheet—not only visual appearance.
A complete inspection can cover:
●Dimensions and quantity
●Steel structure, welding, and coating
●Doors, windows, glazing, and sealant
●Electrical and plumbing systems
●Equipment operation
●Waterproofing details
●Accessories and spare parts
●Packaging and container securing
The value of a factory audit is not simply checking certificates displayed on a wall. It is verifying whether the supplier’s stated production capacity and quality-control process are actually being followed.
15. Put Every Commitment into Contract Attachments
Many disputes in modular house procurement happen not because nothing was delivered, but because the buyer and supplier had different understandings of what was included.
Phrases such as “premium configuration,” “export standard,” or “fully furnished” are too vague to protect either party.
Your contract attachments should clearly define:
●Final drawings and dimensions
●Steel structure, wall, roof, floor, and insulation specifications
●Doors, windows, glass, bathrooms, electrical equipment, furniture, and hardware
●Material brands, models, thicknesses, colors, and quantities
●Production lead time, delivery terms, and acceptance standards
●Warranty coverage for waterproofing, structure, electrical systems, and equipment
●Packaging, container loading, installation guidance, and spare parts
●Procedures for approved design or configuration changes
How CGCH Supports Buyer Verification
A reliable modular building supplier should be open to verification through real documents, production processes, and order-specific technical information—not just product photos and sales promises.
CGCH offers modular building solutions including expandable container houses, folding container houses, flat-pack container houses, detachable container units, capsule houses, and customized modular structures. Because different products have different shipping methods, installation requirements, layouts, and project applications, buyers should first share the project location, intended use, quantity, delivery schedule, site access conditions, and functional requirements.
For custom projects, buyers can confirm the layout, structure, materials, windows, insulation, electrical systems, plumbing, transportation, lifting, and inspection requirements step by step.
CGCH can support early discussions on product options, configuration priorities, and shipping information based on project conditions. Final supply scope, technical standards, lead time, and acceptance criteria should always follow the confirmed quotation, drawings, and contract attachments.
Common Warning Signs
The following signs do not automatically mean that a supplier is unreliable, but they should prompt further verification before payment:
●The supplier refuses to provide a Chinese business license, factory address, or registration number
●The supplier can only show a showroom, sample house, or pre-recorded video
●The quotation is unusually low, but the supplier cannot explain differences in steel, insulation, waterproofing, glass, electrical systems, shipping, or installation scope
●The relationship between the contract company, payment recipient, factory, and export company is unclear
●The quotation does not include drawings, material specifications, dimensions, or acceptance standards
Frequently Asked Questions
How can I verify that a modular house supplier in China has a real factory?
Start by checking the legal company information. Then arrange a live video factory audit to view raw materials, production areas, units under construction, finished products, and container-loading areas. For high-value orders, consider an on-site audit or independent third-party inspection.
What is the most important document when buying a modular house from China?
The most important documents are the order-specific technical attachments: drawings, material specifications, dimensions, equipment lists, shipping plans, inspection standards, and warranty terms. A brochure or rendering is not enough.
Why do modular house quotations from China vary so much?
Price differences often come from steel structure, wall systems, insulation, glass, waterproofing, electrical systems, bathrooms, furniture, shipping method, installation support, and warranty coverage. Ask all suppliers to quote based on the same specification sheet before comparing prices.
Do I need third-party inspection for a capsule house order?
For first-time cooperation, bulk orders, high-value capsule houses, or highly customized projects, third-party inspection is recommended. The inspection should follow the confirmed drawings, specifications, and contract attachments.
Prepare These Details Before Starting Your Project
When contacting CGCH about a modular house, expandable container house, capsule house, prefab container home, or customized modular building project, prepare the following information:
●Project country or region
●Intended use, such as glamping accommodation, resort rooms, worker housing, offices, or commercial space
●Estimated quantity and target delivery date
●Required size, layout, and interior functions
●Whether bathrooms, kitchens, furniture, appliances, and pre-installed plumbing and electrical systems are required
●Site access, foundation conditions, crane access, and utility connection details
The more complete your project information is, the easier it will be to develop a practical product configuration, shipping plan, and quotation.
Email: info@cgreenshouse.com
Website: www.cgchcapsulehouse.com