Interior Doors Manufacturer & Supplier for Builders
As a premier interior door manufacturer and project supplier dedicated to the North American market, UWG delivers a comprehensive suite of interior door solutions—including Molded Doors, Shaker Doors, French Doors, Barn Doors, Bifold Doors, and Fire-Rated Doors—engineered to meet all Division 8 Opening Products project specifications.
Leveraging our vertically integrated manufacturing infrastructure, strategic North American warehousing, and highly stable supply chain capacity, UWG delivers consistent commercial-grade quality, high-volume scalable capacity, and factory-direct pricing for residential, multi-family, and commercial developments—cutting your procurement costs by up to 50% compared to traditional retail channels.
Our Interior Door Collection
Molded Doors
Balancing affordability with high-volume delivery capacity, available in hollow-core and sound-dampening solid-core options. Tight factory tolerances eliminate on-site installation issues .
Veneer Doors
Available in PVC vacuum-laminate and melamine finish options. We deliver zero color variation across production batches, eliminating disputes during large-project closeout inspections.
Shaker Doors
One of UWG's most popular interior door series, finished with a fine, factory-applied white primer coat. Upgrading from a standard molded door to a shaker door instantly elevates a home's perceived value.
Stile and Rail Doors
A solid-wood interior door construction built for premium custom homes. Precision joinery produces a solid, substantial structure with unmatched impact resistance and deep, architectural shadow lines.
Flush Doors
Clean, flat-panel design, available with custom surface treatments including V-groove routing, CNC carving, and vertical/horizontal grooving to match project design requirements.
Glass Doors
A full range of glass configurations compliant with North American safety standards, factory-fitted to the door frame and hardware for optimal daylighting and a modern visual effect.
French Doors
A wide variety of lite layouts, available in both True Divided Lite and Simulated Divided Lite to flexibly fit any project budget.
Louvered Doors
Strict moisture-content control eliminates loose or warped slats, available in both functional (true) and decorative (faux) louver construction.
Barn Doors
A complete door-and-track package, factory pre-drilled and paired with heavy-duty, commercial-grade smooth-glide hardware. Installed on-site with a simple hang-and-mount process, cutting on-site labor costs by 30%.
Double Doors
Any of our core door styles — molded, Shaker, glass, or flush — can be configured as a double door. Factory-calibrated precision eliminates the on-site misalignment issues common with double-door installations.
Bifold Doors
Bifold panels are available across our full range of door styles. Equipped with a heavy-duty anti-derail roller system for smooth, sag-free operation even under frequent daily use.
Sliding Doors
Seamlessly combined with any UWG door style, track system, and finish option. Factory pre-assembled and shipped as a complete project package to simplify on-site logistics.
Pocket Doors
A space-saving system built with a warp-resistant steel-reinforced wood frame and a 200 lb.-rated heavy-duty roller track, eliminating future hardware failures and costly rework.
Fire-Rated Doors
Fully UL-certified from 20 to 90 minutes, built with a high-density mineral fire-resistant core and an intumescent, fire-rated frame to help your project pass fire inspection with confidence.
UWG delivers premium interior doors directly to your jobsite via hassle-free DDP shipping. Backed by our distribution hubs in Houston, TX and Oklahoma City, OK, we ensure seamless staging and rapid local restocking.
Standard Interior Door Sizes, Widths & Specifications
In North American construction projects, dimensional accuracy directly affects on-site installation efficiency. The chart below provides a complete size and rough-opening reference for UWG standard interior hinged doors, barn doors, pocket doors, and bifold doors. For projects with non-standard specifications, the UWG technical team can review and break down your construction drawings and provide custom sizing solutions.
| Option Name | Door Slab Size | Fit Rough Opening Size (w/o jamb) |
Door Thickness | ||
|---|---|---|---|---|---|
| Width | Height | Width | Height | ||
| 18" × 80" | 18" | 80" | 20" | 81 1/2" - 82" | 1 3/8" |
| 24" × 80" | 24" | 80" | 26" | 81 1/2" - 82" | 1 3/8" |
| 26" × 80" | 26" | 80" | 28" | 81 1/2" - 82" | 1 3/8" |
| 28" × 80" | 28" | 80" | 30" | 81 1/2" - 82" | 1 3/8" |
| 30" × 80" | 30" | 80" | 32" | 81 1/2" - 82" | 1 3/8" |
| 32" × 80" | 32" | 80" | 34" | 81 1/2" - 82" | 1 3/8" |
| 34" × 80" | 34" | 80" | 36" | 81 1/2" - 82" | 1 3/8" |
| 36" × 80" | 36" | 80" | 38" | 81 1/2" - 82" | 1 3/8" |
| 18" × 96" | 18" | 96" | 20" | 97 1/2" - 98" | 1 3/8" |
| 24" × 96" | 24" | 96" | 26" | 97 1/2" - 98" | 1 3/8" |
| 26" × 96" | 26" | 96" | 28" | 97 1/2" - 98" | 1 3/8" |
| 28" × 96" | 28" | 96" | 30" | 97 1/2" - 98" | 1 3/8" |
| 30" × 96" | 30" | 96" | 32" | 97 1/2" - 98" | 1 3/8" |
| 32" × 96" | 32" | 96" | 34" | 97 1/2" - 98" | 1 3/8" |
| 34" × 96" | 34" | 96" | 36" | 97 1/2" - 98" | 1 3/8" |
| 36" × 96" | 36" | 96" | 38" | 97 1/2" - 98" | 1 3/8" |
| Barn Door Size | A Fit Opening Width | B Fit Opening Height | C Rail Length | D Inside Jamb to Wall: Minimum |
|---|---|---|---|---|
| 30" × 84" | 26"-28" | 80 1/2" | 72" | 34" |
| 36" × 84" | 28"-34" | 80 1/2" | 78" | 40" |
| 42" × 84" | 38"-40" | 80 1/2" | 84" | 46" |
| 48" × 84" | 44"-46" | 80 1/2" | 96" | 50" |
| 60" × 84" | 56"-58" | 80 1/2" | 72" × 2" | 34" |
| 72" × 84" | 68"-70" | 80 1/2" | 78" × 2" | 40" |
| 84" × 84" | 80"-82" | 80 1/2" | 84" × 2" | 46" |
| 96" × 84" | 92"-94" | 80 1/2" | 96" × 2" | 50" |
| Size | A Width | B Height | Single Panel Width |
|---|---|---|---|
| 24"X80" | 23 1/2" | 79" | 11 3/4" |
| 30"X80" | 29 1/2" | 79" | 14 3/4" |
| 36"X80" | 35 1/2" | 79" | 17 3/4" |
| 48"X80" | 47 1/2" | 79" | 23 3/4" |
| 60"X80" | 59 1/2" | 79" | 39 3/4" |
| 72"X80" | 71 1/2" | 79" | 35 3/4" |
| Door Size | Fit Opening Width | Fit Opening Height | Stud Walls |
|---|---|---|---|
| 24" X 80" | 48 3/8" | 82 3/4" | 2" X 4" |
| 28" X 80" | 56 3/8" | 82 3/4" | 2" X 4" |
| 30" X 80" | 60 3/8" | 82 3/4" | 2" X 4" |
| 32" X 80" | 64 3/8" | 82 3/4" | 2" X 4" |
| 36" X 80" | 72 3/8" | 82 3/4" | 2" X 4 " / 2" X 6 " |
| 30" X 84" | 60 3/8" | 86 3/4" | 2" X 4" |
| 32" X 84" | 64 3/8" | 86 3/4" | 2" X 4" |
| 36" X 84" | 72 3/8" | 86 3/4" | 2" X 4 " / 2" X 6 " |
Unsure what size to choose for your project? Based on our long-term partnership experience with builders, most builders choose 30" × 80" for interior doors, but the actual specific size still needs to be confirmed based on the rough opening and jamb depth. You can directly share your door opening information with us for professional advice, or if you want to know how to choose the right interior door size for your project, you can read this article.
Slab vs Knock Down vs Prehung — Which Do You Need?
| Configuration Type | Includes Frame & Hinges? | On-Site Installation Labor | Logistics & Storage Efficiency | Best-Fit Applications |
|---|---|---|---|---|
| Slab | No |
Highest labor requirement. Requires on-site machining for frames, hinge mortising, and bore holes. |
Maximum space efficiency. Flat-packed for optimized density; yields maximum ocean freight container capacity. |
Renovation/replacement of individual old door leaves, or custom jobsites staffed with highly skilled finish carpenters. |
| Knock Down (KD) | Yes (Frame and door leaf packaged separately) |
Moderate labor. Requires on-site boring, frame assembly, squaring, and hanging. |
High space efficiency. Strikes the perfect balance between international freight costs and jobsite processing workspace. |
Multi-family residential developments and projects facing high-volume transit or storage constraints. |
| Semi-Prehung | Yes (Frame and door leaf packaged separately; pre-machined for hinges and lockset) |
Low labor. No complex alignment needed; simple frame assembly allows for immediate hanging. |
High-volume, multi-family developments with strict transport limitations but demanding high-precision installation standards. | |
| Prehung | Yes (Door leaf arrives pre-installed in the frame from the factory) |
Lowest labor. True plug-and-play execution; ready for immediate structural fastening into the rough opening. |
Lowest space efficiency. Assembled units take up significant volume; yields the lowest ocean freight container capacity. |
New residential construction, fast-track commercial developments, or projects prioritizing compressed schedules and strict field-labor control. |
For ultimate installation speed and high precision, Prehung doors are the top choice. However, for bulk ocean-shipped multi-family projects, KD or Semi-Prehung doors typically strike a better economic balance between container loading capacity and on-site labor hours. Want to learn more about your options?
Read our article: Slab vs. KD vs. Prehung: How to Choose the Right Door Format for Your Project.
Custom Interior Door Solutions for Your Project
From non-standard interior door sizes to core material customization based on budget and performance requirements (honeycomb paper core, particleboard, tubular core, solid-wood strip core, MDF, and more), to custom glass and finish configurations, UWG offers full flexible manufacturing and one-stop custom interior door solutions.
We run a rigorous closed-loop engineering process: our technical team works directly with you to define your custom specifications, produces pre-production samples for approval once final drawings are confirmed, and only moves into full production after sign-off (custom interior door orders require a MOQ of one full container).
For large developers and multi-site builders, we also offer custom packaging, OEM/private-label branding, and dedicated batch management by project — moving complex non-standard fabrication work off the chaotic jobsite and into a controlled factory environment. This not only brings your architect's design intent to life with precision, but significantly reduces on-site labor costs and rework risk.
UWG delivers premium interior doors directly to your jobsite via hassle-free DDP shipping. Backed by our distribution hubs in Houston, TX and Oklahoma City, OK, we ensure seamless staging and rapid local restocking.
Interior Door Project Case Studies
Explore how UWG supports residential, multi-family, and commercial interior door projects—from specification confirmation and door schedule matching to phased delivery.
Why Builders Source Interior Doors from UWG
Factory-Direct Wholesale Interior Doors
UWG has long provided interior door products for major North American retail channels. Some of the products you see on the shelves of mainstream building materials retailers are manufactured under the exact same standard system as UWG. Leveraging our own manufacturing base, streamlined supply chain model, and product strategy focused on core SKUs, UWG cuts out the multi-layered distribution and inventory costs of traditional retail channels, allowing builders to obtain retail-quality interior doors at prices closer to the factory floor, reducing total procurement costs by up to 50%.
Own Manufacturing Facility
UWG directly manages raw materials, production scheduling, and factory inspections. Once project specifications are confirmed, whether it is Slab, KD (Knock-Down), or Prehung systems, all orders are strictly executed within an integrated manufacturing system, significantly reducing communication gaps and batch discrepancies.
Reliable Bulk Interior Door Supply
Unlike supply models that rely on third-party sourcing, UWG owns its interior door manufacturing plant, allowing for direct management of production planning, quality standards, and delivery cadence. We can even coordinate phased deliveries tailored to your project requirements, helping you acquire the products you need in a timely manner according to construction milestones while reducing on-site waiting times and inventory pressure.
Consistent Specifications, Ready for Installation
For different door styles, we establish fixed raw material standards with strict controls over board density, timber grade, and moisture content. For critical production stages, we set fixed parameters—such as door pressing temperature, pressing pressure, polishing level, and primer thickness. An independent CNC machining program is established for every door style to standardize hinge locations, lock hole positions, and machining dimensions, thereby avoiding deviations.
Fully certified with FSC, CARB2, UL 20–90, and CE, meeting mainstream North American building codes and environmental standards. FSC supports project requirements for responsible timber sourcing; CARB Phase 2 fulfills formaldehyde emission requirements for composite wood products; for Fire-Rated Interior Doors, UL 20–90 minute fire-rated configurations are available; and CE documentation can be provided based on applicable products and market requirements. Prior to quotation and formal submission, if your project requires third-party verification, UWG can confirm and supply corresponding Intertek test reports or SGS inspection reports for project approvals and quality documentation checks.
Interior Door Delivery, Packaging & U.S. Warehouse Support
For projects that cannot wait for the factory direct delivery cycle, UWG's U.S. local warehouses located in Houston, TX and Oklahoma City, OK can provide localized replenishment support for standard Interior Door inventory, and stocked products can typically be arranged for shipment within 5–7 working days. For full-container projects, UWG can coordinate Door-to-Door Delivery from factory loading to jobsite delivery.
DDP Door-to-Door Delivery Process
For eligible full-container orders, DDP Shipping can cover factory loading, ocean freight booking, customs clearance, and U.S. domestic trucking delivery. Customers only need to confirm the delivery address, appointment time, and unloading conditions in advance; container arrivals typically require a 3-ton forklift. Loading photos, packing lists, and logistics milestone updates can be provided after shipment.
Project Packaging & Door Schedule Labeling
Door leaves, door frames, casings, and hardware can be matched and packaged according to Slab, KD, or Prehung supply formats. For project orders, products can be precisely labeled according to specific door numbers (Door ID / Opening Number), buildings, floors, or installation areas in the Door Schedule; casings are packaged in independent small boxes and packed together with the corresponding door frames, which greatly facilitates precise on-site verification, efficient distribution, and subsequent rapid installation at the jobsite.
Container Loading Efficiency for Slab, KD & Prehung Doors
Different supply formats affect container loading utilization and ocean freight costs. Slab Doors have the highest loading efficiency; KD Doors strike a balance between container loading capacity and on-site assembly; Prehung Interior Doors occupy a larger volume, but can reduce on-site processes such as frame matching, grooving, and hanging doors. UWG can formulate container loading plans based on door dimensions, door cores, packaging methods, and container types during the quotation stage.
Interior Door Finishes: Primed, Painted,
Veneered & Stained
Primed Doors
Finished at the factory with a fine white primer coat, ready for on-site top-coat painting — significantly reducing labor hours on site.
Best for: budget-focused, high-volume residential projects with uniform on-site spray painting.
Painted Doors
Fully painted at the factory, typically with eco-friendly water-based paint. Zero color variation across production batches eliminates on-site painting and wait time.
Best for: fast-track multi-family or commercial projects that require doors ready to install on delivery.
Veneered Doors
Available in PVC vacuum-laminate or melamine finish, replicating the look of natural wood grain at a lower cost.
Best for: budget-conscious projects that still require strong visual quality.
Stained Doors
Designed for wood-veneer or natural wood-grain doors, preserving the natural grain pattern for a warm, authentic wood finish.
Best for: high-end residential, luxury and custom home projects.
When selecting Interior Door Finishes, builders typically need to strike a balance among On-site Labor Costs, Budget Thresholds, and Asset Class. Choosing a finish process that highly matches the construction milestones not only elevates the premium space of the property, but also significantly controls the comprehensive hidden costs of the supply chain.
The top choice for volume-driven projects and on-site uniform spraying, featuring factory-applied white primer.
Suitable for commercial and residential projects with tight schedules and a demand for immediate installation upon delivery, offering high color consistency.
For projects looking to replicate or preserve wood grain texture, choices can be made between economical Veneered doors and high-end custom Stained doors based on the project positioning.
You can learn more details through How to Choose Interior Door Finish.
Interior Door Hardware
Interior Door Sourcing Guide for Builder
Shaker doors have become one of the most popular interior door styles in modern homes due to their clean lines, timeless appearance, and versatility.
A 30 x 80 interior prehung door is one of the most common sizes in residential construction. While it comes pre-assembled, correct installation is still critical. This guide will walk you through the process step by step, highlight common mistakes, and share practical insights from real installation scenarios.
When selecting interior doors for residential or multifamily projects, builders and general contractors typically choose between three common options: molded doors, shaker doors, and shaker-style molded doors.
From our experience working with builders and distributors, understanding these structural differences is important because the door construction directly affects cost, durability, sound performance, and project positioning.
Interior Door Sourcing FAQ
Everything you need to know about sourcing doors, cabinets, flooring, and more. Our articles and guides help you make informed decisions and stay ahead in your projects.
Factory pricing, ready-to-ship U.S. warehouse stock — everything built to North American construction standards, so your job finishes on time and on budget.