Double Doors Glass: A B2B Buyer’s Guide to Factory Sourcing

13 min read

When a procurement manager sees a spec sheet for a villa project, the line item for “double doors glass” often triggers more questions than any other component. The drawing shows two leaves, a frame, and a glass panel. But the actual product involves a thermal-break profile, a specific glass configuration, multi-point locking hardware, and a finish that must survive coastal salt spray or high-altitude UV exposure.

The buyer who treats double doors glass as a commodity will pay for it later—either in callbacks, failed inspections, or a replacement order that destroys the project margin. This guide covers what those buyers need to know before sending an RFQ.

1. What Is a Double Door Glass System?

A double door glass system (often called a French door or paired door unit) consists of two independent door leaves within a single frame. Typically, one leaf is active and operates daily; the other is inactive and secured with flush bolts at the top and bottom, opening only for furniture moves or ventilation.

The glass panels occupy a significant portion of the door surface—often 60–80% of the total area. That ratio makes the glass specification as important as the frame material.

1.1 Hinged vs. Sliding Configurations

Hinged double doors swing inward or outward. Sliding double doors (also called multi-slide or folding systems) move along tracks. For exterior entryways, hinged systems dominate because they seal better against air and water infiltration.

1.2 Standard Sizing Logic

Most factories produce modular sizes: 1200mm, 1500mm, or 1800mm widths with heights of 2100mm or 2400mm. Non-standard sizes require custom glass cutting and profile fabrication, which adds 10–20% to the unit cost and extends lead time by 1–2 weeks.

2. Glass Selection for Double Doors

The glass panel is the weakest thermal link in any door system. Selecting the right configuration is not about aesthetics—it is about physics.

2.1 Insulated Glass (Double and Triple Glazing)

Insulated glass units (IGUs) combine two or three panes separated by a spacer and sealed with butyl and silicone. The air gap (typically 12mm or 16mm) contains argon or krypton gas to reduce heat transfer.

Glass Configuration	U-Value (W/m²K)	STC Rating	Best For
Single 6mm tempered	5.8	30	Interior use, mild climates
Double 6mm + 12mm air + 6mm	2.8	34	Exterior doors, moderate climates
Double 6mm + 12mm argon + Low-E	1.6	36	Energy-efficient buildings
Triple 4mm + 12mm argon ×2 + Low-E	1.0	39	Cold climates, passive house

2.2 Tempered vs. Laminated Safety Glass

Building codes in most jurisdictions require safety glass in doors and sidelites. Tempered glass breaks into small, blunt pieces upon impact. Laminated glass holds together when shattered because of a PVB interlayer.

For double doors glass, laminated glass is the better security choice. A determined intruder needs multiple impacts to penetrate a laminated panel, whereas tempered glass fails on the first significant strike.

2.3 Low-E Coatings

Low-emissivity coatings reflect long-wave infrared radiation while allowing visible light to pass. The coating position within the IGU matters:

• Position 2 (outer pane, inner face): blocks solar heat—good for warm climates
• Position 3 (inner pane, outer face): retains interior heat—good for cold climates

A double doors glass unit with Low-E on position 3 and argon fill can cut heating costs by 25–30% compared to clear double glazing.

3. Frame Materials Compared

The frame determines structural performance, thermal efficiency, and maintenance requirements.

3.1 Thermal-Break Aluminum

Aluminum is strong, lightweight, and corrosion-resistant. But raw aluminum conducts heat rapidly. Thermal-break profiles separate the interior and exterior aluminum sections with a polyamide strip, creating a barrier that reduces heat transfer.

Key metrics for thermal-break aluminum double doors glass:

• Air-tightness: Class 8 (600 Pa) or higher
• Water-tightness: Class 9A (500 Pa) or higher
• Wind load resistance: Up to 3000 Pa for high-rise applications

3.2 Solid Wood

Solid wood double doors offer an aesthetic that aluminum cannot replicate. Mahogany, oak, and walnut are common choices. The material requires periodic refinishing—typically every 2–3 years for exterior exposure.

Wood is not always the cheapest option. For high-humidity coastal regions, the maintenance cost over a 10-year lifecycle often exceeds the initial price difference. Buyers should calculate total lifecycle cost, not just the purchase price.

3.3 Aluminum-Clad Wood

This hybrid construction combines a structural aluminum shell with a wood interior. The aluminum handles weather exposure; the wood provides interior warmth. Expect to pay 30–50% more than full aluminum for this configuration.

4. Cost Drivers for Double Doors Glass

B2B buyers need a breakdown of what they are paying for. The unit price of a double doors glass system comprises four main elements:

4.1 Glass

Glass Specification	Approximate Cost per m²
Clear 6mm tempered	$25–35
Double glazed, clear	$60–80
Double glazed, Low-E + argon	$90–120
Laminated + double glazed + Low-E	$130–180

4.2 Hardware

Basic hinges and a single-point lock cost $40–80 per set. Multi-point locking systems with shoot bolts, a security cylinder, and concealed hinges range from $150–400. For exterior double doors, multi-point locking is not optional—it is the difference between a door that resists forced entry and one that opens with a screwdriver.

4.3 Frame Material and Finish

Aluminum profiles cost $8–15 per kg. Powder coating adds $8–12 per m² of surface area. Anodized finishes cost slightly more but offer better UV resistance.

Wood frames vary wildly by species. Engineered wood products are more stable and cheaper than solid timber, but they limit the range of acceptable finishes.

4.4 Customization

• Non-standard sizes: +10–20% cost
• Custom RAL colors: +5% cost, minimum order quantities often apply
• Special glass shapes (arches, radius): +30–50% cost

5. Advantages and Disadvantages of Double Doors

5.1 Advantages

• Curb appeal: Double entry doors signal a premium property. Real estate studies indicate a well-designed entryway adds 5–10% to perceived property value.
• Natural light: Two glass panels flood the entry hall with daylight, reducing lighting costs.
• Ventilation: Opening both leaves creates cross-ventilation that single doors cannot match.
• Accessibility: The full-width clear opening accommodates wheelchairs, furniture, and large equipment.

5.2 Disadvantages

• Structural load: The header beam must support the weight of two door units plus the glass. This often requires additional steel reinforcement in the wall above.
• Meeting stile leaks: The vertical joint where the two doors meet is a potential air and water infiltration point. Proper weather stripping and a compression seal are essential.
• Security: The meeting stile is a weak point unless the inactive leaf has flush bolts and both leaves have multi-point locks.
• Space: Hinged double doors need clear floor space for the swing radius—approximately 1.5m × 1.5m for standard 900mm leaves.

5.3 Mitigation Strategies

• Use a structural steel header or a reinforced aluminum transom to distribute the load
• Specify a compression weather strip with a magnetic or EPDM seal at the meeting stile
• Install a multi-point locking system on both leaves
• For tight spaces, consider a sliding or folding double door configuration

6. How to Evaluate Double Doors Glass Suppliers

The supplier evaluation process determines whether your project succeeds or stalls. Use this framework when assessing potential factories.

6.1 The Four-Pillar Assessment

Pillar	What to Check	Red Flags
Manufacturing capability	Production lines, equipment age, capacity per month	No factory photos, vague about equipment
Quality control	Test reports, inspection process, defect rate	No documented QC procedure
Export experience	Customs documentation, shipping partners, target markets	No packing list or proforma invoice samples
Communication	Response time, technical knowledge, willingness to answer questions	Generic responses, no technical details

6.2 Questions to Ask Before Ordering

• What is your monthly production capacity for double doors glass?
• Can you provide test reports for air-tightness, water-tightness, and wind resistance?
• What are your quality control checkpoints during production?
• Do you offer pre-shipment inspection by a third-party agency?
• What is your standard lead time, and what happens if production is delayed?
• Can you adjust profiles and fittings to meet our local building codes?
• What is your MOQ for custom sizes and colors?
• Do you provide full export documentation including packing list, proforma invoice, and bill of lading?

6.3 Avoid Suppliers Who…

• Cannot provide specific test data for their products
• Quote prices that are significantly lower than the market average (quality is being cut somewhere)
• Have no process for handling complaints or warranty claims
• Cannot show you production photos or arrange a factory visit
• Offer no documentation for customs clearance

7. Industry Standards and Certifications

Double doors glass sold internationally should meet recognized performance standards. The specific certification depends on your target market.

Standard	Region	Key Requirement
ISO 9001:2015	International	Quality management system
CE (EN 14351-1)	Europe	Performance characteristics for windows and doors
AAMA/WDMA/CSA 101/I.S.2/A440	North America	Performance grades for windows and doors
NFRC Label	North America	U-factor, SHGC, and VT ratings
AS 2047	Australia	Performance for windows and doors

7.1 What Certifications Actually Mean

CE marking under EN 14351-1 requires the manufacturer to declare performance characteristics including air permeability, water tightness, wind load resistance, and thermal transmittance. A factory that can provide these declarations has documented evidence of product performance.

NFRC labels provide standardized U-factor and solar heat gain coefficient data. For buyers in North America, an NFRC label is essential for energy code compliance.

8. Production Process: From Raw Material to Finished Double Doors Glass

Understanding how double doors glass is manufactured helps buyers identify quality issues before they become costly problems.

8.1 Profile Fabrication

Aluminum profiles are cut to length, machined for drainage holes and hardware locations, then assembled with corner keys and structural sealant. CNC machining centers ensure precise cuts for multi-point locking systems.

8.2 Glass Preparation

Glass panels are cut to size, edge-polished, and washed. For insulated units, the spacer frame is filled with desiccant, sealed with butyl, and the unit is assembled in a controlled environment. Argon gas is injected through a small hole in the spacer, which is then sealed.

8.3 Assembly

The frame is assembled around the glass, hardware is installed, and the door leaves are hung. This stage requires precision—a misaligned hinge will cause the door to sag and the weather strip to fail.

8.4 Surface Treatment

Aluminum frames are powder coated or anodized after fabrication. The powder coating process involves cleaning, pre-treatment, and electrostatic application of the powder, followed by curing at 200°C. The result is a durable finish that resists chipping and fading.

8.5 Final Inspection

A complete double doors glass unit is checked for:

• Dimensional accuracy (±2mm)
• Glass integrity (no chips, cracks, or seal failures)
• Hardware function (smooth operation, proper alignment)
• Weather strip continuity
• Finish quality (no runs, sags, or bare spots)

9. Customization and OEM/ODM Options

B2B buyers rarely order a standard product. Most projects require some degree of customization.

9.1 OEM (Build to Print)

The buyer provides detailed drawings and specifications. The factory manufactures to those exact requirements. This works well when the buyer has an established product design and needs a manufacturing partner.

9.2 ODM (Design Collaboration)

The buyer provides performance requirements and aesthetic direction. The factory’s engineering team develops a product design that meets those requirements. This approach leverages the factory’s manufacturing knowledge to optimize the design for production efficiency.

9.3 Private Label

The factory manufactures the double doors glass under the buyer’s brand name. Packaging, logos, and even hardware branding can be customized.

9.4 What Can Be Customized

• Size: Width, height, and leaf configuration
• Color: Any RAL color for aluminum frames; various wood stains for wood doors
• Glass: Type, thickness, coating, tint, and pattern
• Hardware: Hinges, locks, handles, and accessories from different brands
• Profile structure: Adjustments to meet local building codes and wind load requirements

10. Ordering Process: MOQ, Lead Time, and Shipping

10.1 Minimum Order Quantity (MOQ)

Most factories require an MOQ of 10–20 units for standard products. Custom sizes and colors may require higher MOQs or incur a setup fee.

10.2 Lead Time

Order Type	Typical Lead Time
Standard sizes, stock colors	15–20 days
Custom sizes, stock colors	20–30 days
Custom sizes, custom colors	30–40 days
Full container (FCL)	30–45 days

10.3 Shipping: FCL vs. LCL

• LCL (Less than Container Load): For smaller orders. You share container space with other shipments. Cost is based on volume (CBM). Risk of damage is higher because your goods are handled alongside other cargo.
• FCL (Full Container Load): For larger orders. The entire container is yours. Safer for fragile items like glass, and more cost-effective per unit at scale.

10.4 Export Documentation

A reliable factory provides:

• Packing list
• Proforma invoice
• Commercial invoice
• Bill of lading
• Certificate of origin (if applicable)
• Test reports and certificates

11. How We Meet These Standards: A Factory Perspective

The standards described above are not theoretical. They are the operational baseline for our production facility at Jusen Door and Windows Manufacturing Co., Ltd.

11.1 Direct Factory Supply

We manufacture double doors glass and related products in our own facility. There is no distributor markup between our production line and your project. When you request a quote, you receive the factory-direct price. This matters for B2B buyers who need to protect project margins.

11.2 Customization Without Compromise

Our production line supports full customization—size, color, glass configuration, and hardware. We manufacture thermal-break aluminum systems, solid wood doors, and aluminum-clad wood combinations. Whether you need an OEM build-to-print or an ODM design collaboration, our engineering team works from your performance requirements.

11.3 Quality Assurance and Compliance

Every double doors glass unit undergoes pre-shipment inspection. We test for air-tightness, water-tightness, and wind resistance using calibrated equipment. Our export team provides complete documentation—packing list, proforma invoice, and customs paperwork—to ensure smooth clearance at your destination port.

We adjust profile structures and fittings to match the building codes of your target market. If your project requires CE marking or AAMA certification, we can manufacture to those specifications.

11.4 Shipping Options

We handle both FCL and LCL shipments. For fragile glass products, we recommend FCL to minimize handling and damage risk. Our shipping partners provide tracking so you know exactly when your order will arrive.

11.5 A Real Project Example

A European distributor approached us with a requirement for 200 units of double doors glass for a residential development. The spec called for thermal-break aluminum frames, triple glazing with argon fill, and multi-point locking systems. We produced the units in 45 days, provided full CE documentation, and shipped via FCL to Rotterdam. The distributor reordered 300 units for their next project.

12. Decision Guide: Choosing the Right Configuration

Choose a thermal-break aluminum double door if:

• The project is in a coastal or high-humidity area
• The building is more than 3 stories (wind load is a factor)
• Low maintenance is a priority
• The budget requires a cost-effective solution

Choose a solid wood double door if:

• The project is a luxury villa or heritage building
• The client values traditional aesthetics
• The budget accommodates higher cost and ongoing maintenance

Choose an aluminum-clad wood double door if:

• The interior demands wood warmth but the exterior requires aluminum durability
• The project budget allows for the premium price

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Frequently Asked Questions

Are double front doors a good idea?

From a B2B perspective, yes—they increase property value and curb appeal significantly. However, they require careful structural engineering for the header and hinges to handle the additional weight compared to a single door. The meeting stile also needs proper weather stripping and multi-point locks.

What do you call a front door that has two doors?

In the industry, this configuration is typically called a “double door” or “French door” (if hinged and opening from the center). In technical specifications, it is often referred to as a “paired door unit” or “double leaf door.”

How much do new double front doors cost?

Costs vary based on material and glass. Aluminum double doors glass might range from $1,500 to $4,000 per unit, while solid wood or custom thermal-break systems with high-performance glass can exceed $8,000. For B2B pricing, volume and customization levels are the primary cost drivers.

What are the disadvantages of double doors?

The main drawbacks are structural (the header must support the weight), security (the meeting stile is a potential weak point), and thermal bridging (air leaks at the center). These issues are mitigated with proper engineering and multi-point locking hardware.

What is the difference between LCL and FCL shipping for glass doors?

LCL (Less than Container Load) is for smaller orders where you share container space with other goods, paying for the volume you use. FCL (Full Container Load) is for larger orders where you rent the entire container. FCL is generally safer for fragile items like glass and more cost-effective per unit at scale.

Can I get custom sizes for double doors glass?

Yes. Most factories offer full customization on size. However, non-standard sizes may increase lead time and cost due to custom glass cutting and profile fabrication. Confirm your exact opening dimensions with the factory before ordering.

Do you provide documentation for customs clearance?

Yes, as an export-oriented factory, we provide a packing list, proforma invoice, bill of lading, and other necessary customs documents to ensure smooth clearance in your destination country.

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The decision on double doors glass comes down to three factors: performance requirements, budget constraints, and supplier reliability. A factory that can demonstrate test data, provide documentation, and communicate clearly through the production process is worth more than a slightly lower quote from an unverified source.

Discuss your project parameters—size, performance requirements, and volume—with our team to get accurate pricing and lead times for your specific needs.

Get a Free Quote

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References

• ISO 9001:2015 Quality Management Systems — https://www.iso.org/standard/62085.html
• EN 14351-1:2006+A2:2010 Windows and doors — Product standard — https://www.en-standard.eu/
• AAMA/WDMA/CSA 101/I.S.2/A440 — North American Fenestration Standard — https://www.aamanet.org/
• NFRC Label Certification — https://www.nfrc.org/
• AS 2047 Windows and doors — Performance requirements — https://www.standards.org.au/
• Glass for Europe — Insulating Glass Units — https://www.glassforeurope.com/
• Efficient Windows Collaborative — Low-E Coatings — https://efficientwindows.org/