Building Types
100x120 Manufacturing Steel Building
- Width
- 100 ft
- Length
- 120 ft
- Floor area
- 12,000 sq ft
- Perimeter
- 440 ft
Quick dimensions
At a Glance
Width
100 ft across the gable end.
Length
120 ft along the sidewall.
Floor area
12,000 sq ft of clear floor.
Eave height
14 ft at the sidewall on the stored profile.
Configuration
How This Building Is Configured
Configuration summary
| Building type | Manufacturing Building |
|---|---|
| Footprint | 100 ft × 120 ft |
| Floor area | 12,000 sq ft |
| Eave height | 14 ft |
Planning
Footprint & Space Planning
Footprint
Width and length are chosen together: width is usually fixed by what has to fit side by side, length by how many bays are needed.
Height
Eave height is commonly the governing dimension here, because clearance for the tallest item sets the door and the wall.
Access
Where vehicles and people enter changes the whole interior layout, so access is settled before anything else.
Doors and openings
Opening width, height and position are specified with the supplier; they affect the frame and the wall bracing.
Site
Slope, drainage, access for delivery and erection, and the foundation are confirmed for the actual property.
Expansion
Extending along the length is usually simpler than changing the width later, which is worth deciding up front.
Use
How a 100×120 Manufacturing Building May Be Used
Production or storage flow
Material entering one end and leaving the other is a common organising principle.
Loading access
Dock or grade-level door placement is usually decided before the frame layout.
Racking and clear height
Usable stacking height depends on eave height and any interior structure.
Equipment and services
Power, compressed air and lighting layouts follow the bay spacing.
Example
Example Configuration
Access
Doors & Access Considerations
Opening width
Across a 100 ft gable end, the practical opening width is limited by the frame and confirmed with the supplier.
Opening height
A 14 ft eave sets the ceiling on door height before any frame change.
Drive-through
Matching openings at both ends avoid reversing, at the cost of usable wall.
Similar sizes
Other Sizes for a Manufacturing Building
100′ × 100′
10,000 sq ft
100′ × 140′
14,000 sq ft
90′ × 120′
10,800 sq ft
Related
Related Building Types
Example configuration — for planning purposes only.
FAQ
Common Questions
100 ft × 120 ft is 12,000 square feet of floor area before any interior partitions.
Length is usually adjusted in bay increments, and width is a larger design change. Both are confirmed with the supplier for the final design.
Site preparation, foundation and erection are commonly quoted separately from the building package. Confirm the scope of any quote you receive.
Compare nearby sizes
Related footprints for this building type
Each page works through one footprint for one building type.
Cost drivers
Quantities that move the estimate at 100x120
The estimate at 100x120 moves with four computed quantities: 12,000 square feet of floor, 440 feet of perimeter, 6,160 square feet of wall and 12,369 square feet of roof. Everything else is site and specification. Plan the exit as carefully as the entrance; buildings are emptied under more time pressure than they are filled.
The finishing end carries the disproportionate cost: air handling, lighting, surfaces and separation. Planning it as a defined area rather than as a portion of the floor is what keeps that cost contained.
- clear height for machine access and overhead handling
- power capacity for the equipment set
- foundation and slab requirements under machines, which are engineering items
- extraction at process positions
Overview
A 100x120 manufacturing building planned as an assembly floor with a separated finishing end
This page is ordered around the boundary between the dirty end and the clean end, because that line determines airflow, traffic and both openings.
The footprint holds 12 assembly positions — 4 across by 3 deep — and the remaining 10 feet is marginal: there is no separated finishing end, so finishing happens on the assembly floor and is scheduled around it rather than run alongside it.
Commitment first: 70% of the 12,000 square feet goes to assembly positions at 704 square feet each, and 2,440 square feet survives as edge strip. A footprint is worth its own decision when that split lands where the work does. An empty building looks generous and a working one rarely does; plan against the working state.
A 100 by 120 footprint is a mildly directional plan: 12,000 sq ft enclosed by 440 ft of wall, at a 1.2:1 length-to-width proportion. Along its 120 ft dimension it takes 3 runs of assembly positions at 32 ft, leaving 24 ft over — the 24 ft is where the argument about this size actually happens. Where assembly is followed by finishing, the plan's real subject is the boundary between them. Dust, traffic and handling belong on one side; finished surfaces, inspection and packing belong on the other, and the two want different air, different lighting and different floor. A production plan is judged on sequence and interruption, not on floor area.
At 100x120 the operating question is a specific one: can this plan keep the clean end genuinely clean, or does the finished work share air and traffic with the work that generates dust? That is a different question from the one a manufacturing building of another shape has to answer, and it is why this footprint is planned as an assembly floor with a separated finishing end rather than as generic covered area.
Areas, perimeter, roof area, ridge height, slab volume and the assembly position counts on this page are computed from the stored 100x120 record and this platform's planning module for the manufacturing building category.
Configurations
Configuring 12 assembly positions at 100x120
At 24-foot nominal bays the structure works with the layout instead of against it: one assembly position per bay line, walls free of awkward half-positions. The plan should survive the day the largest item the operation owns has to come inside.
With 3 rows deep, the rear row is behind the front one. Without a route past it, those assembly positions become storage positions rather than working ones — the real cost of depth at this width. A leftover strip earns its place only when something is deliberately put in it; otherwise it is circulation with a nicer name.
Extension is cheapest along the 120 ft dimension, where each added bay repeats work already framed; widening past 100 ft is a different frame rather than a longer one. Growing to 100 by 152 adds a 4th run of assembly positions — useful if the constraint is assembly positions rather than the 24 ft already spare at the far end.
Configured as an assembly floor with a separated finishing end, 100x120 is judged on whether the 12 assembly positions it holds match the operation, and on whether the 12 feet of spare width leaves the route this mode depends on.
- Does the work need an interior street with independent zones on both sides and turning room at each end, or does it need a second lane that this 100-foot span cannot give?
- Is the 120-foot length being bought for depth, or for the repeated bays — a long repeating bay sequence, so segment boundaries are set by bay lines rather than by walls?
- Is the machine list fixed, and has the line order been drawn before the building?
- Can a machine be removed and replaced without shutting the line?
Bay division shown here is a planning module computed from the stored length. Actual bay spacing is set by the manufacturer's frame design for the building.
Allocation
Dividing the floor for an assembly floor with a separated finishing end
The production arrangement this floor could equally be laid out for is a fabrication floor working in batches rather than in continuous flow: there is no separate work-in-progress area, so part-finished batches stand in the bays and reduce the floor available for the next job. Dividing the 12,000 sq ft by the 22 by 32 ft assembly position gives roughly 9 positions before circulation is deducted a second time for cross movement. Whether the plan keeps 9 or drops to 6 comes back to the question this footprint is really answering: can this plan keep the clean end genuinely clean, or does the finished work share air and traffic with the work that generates dust?
There is no end zone at this footprint. 10 feet is circulation slack, not floor area with a purpose, and there is no separated finishing end, so finishing happens on the assembly floor and is scheduled around it rather than run alongside it. Ground conditions and drainage decide the floor before the frame does.
Spare width is the more valuable of the two leftovers here: a continuous 12-foot strip beats the same area stranded at the end of the run, because it touches every position along the way. Neighbouring buildings, setbacks and the approach road often decide the orientation before the plan does.
At 1.2:1 the plan is close enough to square that neither width nor depth is doing the arguing; what decides the layout here is where the openings go, because no proportion is forcing a direction on the floor. Spent as a square 110 by 110 instead, the same 12,000 sq ft would stand 4 assembly positions across rather than 3, and would trade this plan's length for parallel access. That is the width-against-depth decision this footprint has already made. A building of this size behaves like a small yard under a roof: zones need to be defined, signed and left alone, or they migrate. The longest internal travel on a 100 by 120 plan is about 156 ft corner to corner, and the shortest useful one is the 100 ft cross-run. For a an assembly floor with a separated finishing end that matters where assembly and finishing layout sits, because shortening the 100 ft run to serve it lengthens every trip along the 120 ft dimension. Inspection and quality positions need daylight or specified lighting and are usually allocated last, which is why they end up in the worst corner. That movement pattern, not the 12,000-square-foot total, is what decides whether the leftover 10 feet is useful here.
Openings
Openings for 4 assembly positions across
The 100-foot gable can carry 4 openings, one per assembly position, with 12 feet of wall left for piers between and beside them — the arrangement that keeps each position independently reachable. What the building holds in its busiest week is the honest brief; the rest of the year is slack.
Two openings — material in at the assembly end, product out at the finished end — are what let the one-way pattern hold. Any ventilation or extraction provision for finishing is designed for the specific process and building.
Material received at the head of the line and product shipped from the tail, which is what keeps the two flows from colliding.
Framed-opening sizes, headers and the structure around them are engineered for the specific building. Confirm every opening with the door supplier and the building manufacturer before ordering.
Usable area
How the 12,000 square feet divides at 100x120
Computed assembly position fit for a 100x120 manufacturing building
| Measure | Computed at this footprint |
|---|---|
| Assembly positions across the 100-foot width | 4 at a 22-foot module |
| Leftover width | 12 ft (1,440 sq ft as a full-length strip) |
| Rows along the 120-foot length | 3 at a 32-foot module after 14 ft of circulation |
| Leftover depth | 10 ft (1,000 sq ft across the width) |
| Total assembly positions | 12 |
| Share of floor committed | 70% |
Module footprint used here is 22 by 32 feet, this platform's planning module for a manufacturing building. It is not a code minimum or an engineered clearance.
Example allocation of the 120-foot length — planning model, not survey data
| Zone | Length along the building | Computed area |
|---|---|---|
| Production floor | 66 ft | 6,600 sq ft |
| Material handling and staging | 33.6 ft | 3,360 sq ft |
| Support, office and utility | 20.4 ft | 2,040 sq ft |
Shares applied to the stored 120-foot length; areas computed against the 100-foot width.
Module footprints and allocation shares come from this platform's use typology and are published as example planning models. They are not recommendations and do not describe a majority of projects.
Height
Interior height for a 100x120 manufacturing building
The stored configuration carries a 14-foot eave and computes to 26.5 feet at the ridge on a 3:12 pitch — a 12.5-foot rise across 100 feet. Height is therefore not uniform, and the sidewall is the constraint. The corner nobody plans for is the one that fills first, which is an argument for planning it.
Height on a 100 ft span is a separate decision from the 120 ft length, and it is the span that sets the frame's behavior. Raising the eave over 12,000 sq ft affects every bay along the 120 ft dimension, so the test is whether assembly and finishing layout genuinely needs the extra clear height or only the floor area.
Ventilation across 12,000 square feet at this height: process extraction at machine positions, planned with the equipment rather than after it.
Clear height below purlins, bracing and lighting is lower than the eave height. The usable figure comes from the manufacturer's framing for the selected building.
Comparison
What changes at adjacent footprints
Computed comparison of nearby footprints for a manufacturing building
| Footprint | Floor area | Assembly positions |
|---|---|---|
| 60x80 | 4,800 sq ft | 2 (2 x 1) |
| 40x120 | 4,800 sq ft | 8 (2 x 4) |
| 50x100 | 5,000 sq ft | 6 (2 x 3) |
| 60x100 | 6,000 sq ft | 4 (2 x 2) |
| 50x120 | 6,000 sq ft | 8 (2 x 4) |
Areas computed from each stored size record; assembly position counts computed with the same 22 by 32 foot planning module.
- 60x80 moves the count from 12 to 2 assembly positions (2 across by 1 deep), which is the reason to choose between them.
- 40x120 moves the count from 12 to 8 assembly positions (2 across by 4 deep), which is the reason to choose between them.
- 50x100 moves the count from 12 to 6 assembly positions (2 across by 3 deep), which is the reason to choose between them.
Nearby footprints read for a manufacturing building: exact change in area and in planning assembly positions
| Footprint | Area Δ | % Δ | Assembly positions at that footprint | What changes for this use |
|---|---|---|---|---|
| 100x100 | −2,000 sq ft | −16.7% | 8 (4 x 2) | −4 assembly positions on the same planning module. |
| 80x120 | −2,400 sq ft | −20% | 9 (3 x 3) | −3 assembly positions on the same planning module. |
| 100x150 | +3,000 sq ft | +25% | 20 (5 x 4) | +8 assembly positions on the same planning module. |
Areas are arithmetic on two stored size records; assembly position counts use this platform's 22 by 32 foot planning module and are not a capacity statement.
Because this footprint is planned as an assembly floor with a separated finishing end, the useful next reads are different from the ones a differently shaped manufacturing building suggests: assembly and finishing layout, clean end separation, one-way production route.
Visualization
Reading the 100x120 footprint as a manufacturing building
FAQ
Questions about 100x120 manufacturing building projects
The footprint holds 12 assembly positions — 4 across by 3 deep — and the remaining 10 feet is marginal: there is no separated finishing end, so finishing happens on the assembly floor and is scheduled around it rather than run alongside it. Those counts use a 22 by 32 foot planning module with 14 feet allowed for circulation, so a different module changes the answer.
Reserving 14 ft across the 100 ft dimension for movement leaves 86 ft of working width, which takes 3 assembly positions at 22 ft. Along 120 ft it takes 3 runs at 32 ft. That is 9 positions out of 12,000 sq ft, and the remainder is circulation, walls and the margin every plan needs. Whether that count is enough depends on can this plan keep the clean end genuinely clean, or does the finished work share air and traffic with the work that generates dust. These are planning figures computed from the footprint, not a quoted layout.
A 4-inch slab across 12,000 square feet computes to 148.1 cubic yards before thickened edges, piers or waste. The final design comes from the foundation engineer.
It needs its own route back, planned deliberately. Without one it travels through the clean end, which is exactly the traffic the layout exists to prevent.
6,160 square feet of wall and 12,369 square feet of roof at a 3:12 pitch — the roof exceeding the floor by 3%.
Methodology
How this page was produced
Sources and methodology
Find Steel Buildings dimensional records
Find Steel Buildings · Primary platform dataset · Tier 1 — code authority, standards body, primary dataset or manufacturer engineering
Supports: Stored nominal width, length, eave height, roof pitch and slab thickness for this subject.
International Building Code and International Residential Code
International Code Council · Model code · Tier 1 — code authority, standards body, primary dataset or manufacturer engineering
Supports: The framework of adopted codes and local amendments that decides permitting, separation and opening requirements. Cited as the governing framework, never as a local requirement.
- Dimensional figures: Width, length, eave height, roof pitch and nominal slab thickness come from this platform's stored record for the subject. Floor area, perimeter, wall area, roof area, ridge height and slab volume are computed from those inputs rather than transcribed.
- Assembly position fit: Counts, leftover strips and per-module areas are computed from the stored 100x120 record against this platform's 22 by 32 foot planning module for the manufacturing building category, with 14 feet allowed for circulation. The module is editorial planning typology, not a code minimum or an engineered clearance.
- Allocation model: Zone shares come from this platform's use typology for production and industrial operations and are applied arithmetically to the stored 120-foot length.
- Allocation and layout models: Layout splits are arithmetic on the stored footprint, published as example allocation models. They are not survey findings and do not describe what buyers most often choose.
- Clearance and opening guidance: Clearance and opening statements are planning guidance. Final dimensions depend on the selected door system, header detail and the manufacturer's engineering for the building.
Methodology notes
- Prices: No price figure appears on this page. Cost data is published on this platform only with a documented inclusion basis, a collection date and a named source.
Drawn to scale
Plans and dimensions
Every drawing below is generated from the exact dimensions for this building, so proportions and areas are accurate.
Compare 100x120 manufacturing building configurations
Review the allocation models for this footprint side by side, then estimate the configuration you intend to build.