Prefabricated Wall Panels: Choose Your Level of Factory Completion
Module Building Systems
MBS offers several levels of factory preparation: framing subcomponents, bare framed panels and sheathed panels. More complete assemblies can include additional envelope elements or services when specified. The right package depends on what your crew wants prepared in the factory and what it will complete on site.
That is the whole argument for advanced panelized construction. It is also the part most developers have never seen.
Offsite methods still account for just 3% of U.S. single-family home completions, according to NAHB analysis of Census Bureau Survey of Construction data. Interest in the category is high. Familiarity is low. So here is exactly what a prefabricated wall panel is, what is inside one when it leaves our 40,000 ft2 CNC manufacturing facility, and what that changes on your schedule.
What is a prefabricated wall panel?
A prefabricated wall panel is a wall assembly prepared in a factory and shipped to the job site. It may be bare framing, framing with specified sheathing, or a more complete assembly. The agreed project scope determines which materials and services are installed before delivery.
Panelized construction builds a building in flat pieces. Modular construction builds it in finished three-dimensional boxes. Stick-built construction builds it, board by board, outdoors, in the weather. Panels give you factory quality without the freight cost and site constraints that come with shipping finished boxes. Our FAQ covers the method comparison in more detail.
Open panel vs closed panel construction
The industry grades panels by how much work is already done when the truck arrives.
- Open panel. Frame and sheathing only. Insulation, membranes, wiring, plumbing, windows, and finishes all still happen on site.
- Closed panel. Insulation, sheathing, and membranes are installed in the factory. Service voids and conduit runs are built in. Window and door openings are formed and often glazed before shipping.
MBS offers several levels of factory completion. Additional envelope components and MEP preparation are available when included in the agreed package. The site crew sets the wall and makes the connections. See how the process runs from design to assembly on our services page.
What can be inside an MBS panel when it ships
- CNC-cut structural frame. Cut to engineered tolerances by machine, not measured and cut in a muddy yard.
- Sheathing. On sheathed and closed panels, applied and fastened flat, so the panel is square and stays square.
- Insulation. When included, installed indoors with consistent fill and no weather exposure before close-in.
- Windows. When included, glazed, set and sealed into the opening before the panel is loaded.
- Doors. When included, hung in the opening, square and ready to trim.
- Exterior cladding. Factory application is available where cladding is included in the agreed panel package.
- MEP. When included, conduit, boxes and plumbing runs are installed in the panel, so electricians and plumbers connect instead of rough in.
Why factory finishing changes the schedule
Up to 50% faster construction schedules compared with traditional construction. Actual schedules depend on project scope, approvals, site readiness, materials and logistics.
The reason is sequencing. On a stick-built site, trades work in series. Framing waits on the slab. Sheathing waits on framing. Windows wait on sheathing. Insulation waits on windows. Every one of those steps also waits on the weather.
In a factory, those steps run in parallel across stations under one roof, on a fixed schedule, indoors. Rain does not stop a station. A late trade does not idle the whole job. That is how panelized construction delivers up to 30% lower project cost, up to 50% faster construction schedules compared with traditional construction, and up to 90% less waste. Actual schedules depend on project scope, approvals, site readiness, materials and logistics. Our solutions page breaks down where each of those savings comes from.
How finished panels ship
Panels ship flat-packed and vertically on standard flatbeds. No oversize loads. No escort vehicles. No craning a finished box down a narrow residential street.
MBS ships within 1,000 miles of our St. Louis facility, which covers most of the eastern half of the country. Panels arrive in installation sequence, so the crew unloads and sets in order rather than staging, sorting, and double-handling material on a tight site.
What this means for developers, GCs, and municipalities
- Cost certainty. Panels are priced at the factory before the first truck moves. Fixed factory pricing removes most of the change-order exposure that lives in field labor.
- A smaller site crew. Most of the labor happens in the plant. The site team is smaller, the work is safer, and the schedule depends on fewer subcontractors showing up.
- A lockdown date you can plan around. Up to 50% faster construction schedules compared with traditional construction. Actual schedules depend on project scope, approvals, site readiness, materials and logistics.
- Repeatable quality. The hundredth panel is built the same way as the first. That matters most on multi-unit and scattered-site affordable housing.
The same finished-panel system builds single-family homes, ADUs, tiny homes, townhomes, mixed-use buildings, temporary and disaster-relief structures, and high-density multi-residential projects from one to six stories. See the full range on our products page.
Frequently asked questions
What is the difference between open panel and closed panel construction?
An open panel is framing, often with sheathing, with insulation, wiring, windows and finishes left for the site. A closed panel arrives with insulation, membranes, windows and MEP rough-in installed in the factory. MBS sells both, plus framing subcomponents, and the agreed package sets what is included.
Do prefabricated wall panels come with windows already installed?
Windows, doors and exterior cladding can be factory-installed when included in the agreed package. Bare framed and sheathed panel packages leave those tasks to the site team. Up to 50% faster construction schedules compared with traditional construction. Actual schedules depend on project scope, approvals, site readiness, materials and logistics.
Are prefabricated wall panels code compliant?
Yes. Panelized construction is a manufacturing method, not a separate code path. Panels are engineered and built to the building code that applies at the project site, and the finished building is inspected like any other construction.
How far can panelized wall panels be shipped?
MBS ships flat-packed panels within 1,000 miles of its St. Louis, Missouri facility on standard flatbeds. Panels load vertically and flat-packed, so a standard trailer carries a full load without oversize permits.
How much construction waste does panelized construction avoid?
Up to 90% less waste than conventional site building. Factory cutting is optimized across the whole project, offcuts are captured and reused, and material does not sit outside, exposed to the weather.
Choose the panel package that fits your project.
Module Building Systems is an advanced panelized construction manufacturer at 921 N 20th Street, St. Louis, MO 63106, founded in 2023. We build wall and floor panel packages for developers, general contractors, non-profit developers, municipalities, and states. Learn more about MBS.
Tell us about your project, and we will price it. Get a quote or email info@modulebs.com.
Explore MBS Panels & Components and send plans for a project-specific supply quote.
MBS offers several levels of factory preparation: framing subcomponents, bare framed panels and sheathed panels. More complete assemblies can include additional envelope elements or services when specified. The right package depends on what your crew wants prepared in the factory and what it will complete on site.
That is the whole argument for advanced panelized construction. It is also the part most developers have never seen.
Offsite methods still account for just 3% of U.S. single-family home completions, according to NAHB analysis of Census Bureau Survey of Construction data. Interest in the category is high. Familiarity is low. So here is exactly what a prefabricated wall panel is, what is inside one when it leaves our 40,000 ft2 CNC manufacturing facility, and what that changes on your schedule.
What is a prefabricated wall panel?
A prefabricated wall panel is a wall assembly prepared in a factory and shipped to the job site. It may be bare framing, framing with specified sheathing, or a more complete assembly. The agreed project scope determines which materials and services are installed before delivery.
Panelized construction builds a building in flat pieces. Modular construction builds it in finished three-dimensional boxes. Stick-built construction builds it, board by board, outdoors, in the weather. Panels give you factory quality without the freight cost and site constraints that come with shipping finished boxes. Our FAQ covers the method comparison in more detail.
Open panel vs closed panel construction
The industry grades panels by how much work is already done when the truck arrives.
- Open panel. Frame and sheathing only. Insulation, membranes, wiring, plumbing, windows, and finishes all still happen on site.
- Closed panel. Insulation, sheathing, and membranes are installed in the factory. Service voids and conduit runs are built in. Window and door openings are formed and often glazed before shipping.
MBS offers several levels of factory completion. Additional envelope components and MEP preparation are available when included in the agreed package. The site crew sets the wall and makes the connections. See how the process runs from design to assembly on our services page.
What can be inside an MBS panel when it ships
- CNC-cut structural frame. Cut to engineered tolerances by machine, not measured and cut in a muddy yard.
- Sheathing. On sheathed and closed panels, applied and fastened flat, so the panel is square and stays square.
- Insulation. When included, installed indoors with consistent fill and no weather exposure before close-in.
- Windows. When included, glazed, set and sealed into the opening before the panel is loaded.
- Doors. When included, hung in the opening, square and ready to trim.
- Exterior cladding. Factory application is available where cladding is included in the agreed panel package.
- MEP. When included, conduit, boxes and plumbing runs are installed in the panel, so electricians and plumbers connect instead of rough in.
Why factory finishing changes the schedule
Up to 50% faster construction schedules compared with traditional construction. Actual schedules depend on project scope, approvals, site readiness, materials and logistics.
The reason is sequencing. On a stick-built site, trades work in series. Framing waits on the slab. Sheathing waits on framing. Windows wait on sheathing. Insulation waits on windows. Every one of those steps also waits on the weather.
In a factory, those steps run in parallel across stations under one roof, on a fixed schedule, indoors. Rain does not stop a station. A late trade does not idle the whole job. That is how panelized construction delivers up to 30% lower project cost, up to 50% faster construction schedules compared with traditional construction, and up to 90% less waste. Actual schedules depend on project scope, approvals, site readiness, materials and logistics. Our solutions page breaks down where each of those savings comes from.
How finished panels ship
Panels ship flat-packed and vertically on standard flatbeds. No oversize loads. No escort vehicles. No craning a finished box down a narrow residential street.
MBS ships within 1,000 miles of our St. Louis facility, which covers most of the eastern half of the country. Panels arrive in installation sequence, so the crew unloads and sets in order rather than staging, sorting, and double-handling material on a tight site.
What this means for developers, GCs, and municipalities
- Cost certainty. Panels are priced at the factory before the first truck moves. Fixed factory pricing removes most of the change-order exposure that lives in field labor.
- A smaller site crew. Most of the labor happens in the plant. The site team is smaller, the work is safer, and the schedule depends on fewer subcontractors showing up.
- A lockdown date you can plan around. Up to 50% faster construction schedules compared with traditional construction. Actual schedules depend on project scope, approvals, site readiness, materials and logistics.
- Repeatable quality. The hundredth panel is built the same way as the first. That matters most on multi-unit and scattered-site affordable housing.
The same finished-panel system builds single-family homes, ADUs, tiny homes, townhomes, mixed-use buildings, temporary and disaster-relief structures, and high-density multi-residential projects from one to six stories. See the full range on our products page.
Frequently asked questions
What is the difference between open panel and closed panel construction?
An open panel is framing, often with sheathing, with insulation, wiring, windows and finishes left for the site. A closed panel arrives with insulation, membranes, windows and MEP rough-in installed in the factory. MBS sells both, plus framing subcomponents, and the agreed package sets what is included.
Do prefabricated wall panels come with windows already installed?
Windows, doors and exterior cladding can be factory-installed when included in the agreed package. Bare framed and sheathed panel packages leave those tasks to the site team. Up to 50% faster construction schedules compared with traditional construction. Actual schedules depend on project scope, approvals, site readiness, materials and logistics.
Are prefabricated wall panels code compliant?
Yes. Panelized construction is a manufacturing method, not a separate code path. Panels are engineered and built to the building code that applies at the project site, and the finished building is inspected like any other construction.
How far can panelized wall panels be shipped?
MBS ships flat-packed panels within 1,000 miles of its St. Louis, Missouri facility on standard flatbeds. Panels load vertically and flat-packed, so a standard trailer carries a full load without oversize permits.
How much construction waste does panelized construction avoid?
Up to 90% less waste than conventional site building. Factory cutting is optimized across the whole project, offcuts are captured and reused, and material does not sit outside, exposed to the weather.
Choose the panel package that fits your project.
Module Building Systems is an advanced panelized construction manufacturer at 921 N 20th Street, St. Louis, MO 63106, founded in 2023. We build wall and floor panel packages for developers, general contractors, non-profit developers, municipalities, and states. Learn more about MBS.
Tell us about your project, and we will price it. Get a quote or email info@modulebs.com.
Explore MBS Panels & Components and send plans for a project-specific supply quote.