100x120 Industrial Steel Building

No price appears on this page. The quantities that scale an estimate at 100x120 are 12,000 square feet of slab, 148.1 cubic yards of nominal concrete, 6,160 square feet of wall cladding and 12,369 square feet of roof cladding. Utilities entering on the wrong elevation quietly rewrite the interior layout.

Frame, wall area, conditioning volume and access equipment all scale with height, so a tall shell costs more per square foot than a low one of the same footprint. That premium is worth paying only over the area that uses it.

• clear height for plant and handling
• power capacity and distribution to plant positions
• slab requirements under fixed equipment, which are an engineering item
• opening positions at the flow ends

This page is ordered around height, because it is the most expensive dimension in this building and the least evenly used part of it.

The footprint holds 3 high bays — 3 across by 1 deep — and leaves 46 feet of depth for a low-level fitted band — offices, stores, plant — with usable volume above it inside the same shell.

Read this footprint through its span. 100 feet across is the fixed constraint; 120 feet of length is the negotiable one, and at 1.2 to 1 the building is close to square, so movement runs in both directions. Neighbouring buildings, setbacks and the approach road often decide the orientation before the plan does.

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 2 runs of high bays at 50 ft, leaving 20 ft over — the 20 ft is where the argument about this size actually happens. Height is the most expensive dimension in an industrial shell and the least evenly used. A tall building earns its cost when the volume is worked — stacked, lifted through or served by equipment at height — and wastes it when the same volume stands empty over an office corridor. The yard usually decides more about an industrial building's performance than the interior layout does.

At 100x120 the operating question is a specific one: which parts of this building genuinely need the height, and what is placed under the parts that do not? That is a different question from the one a industrial building of another shape has to answer, and it is why this footprint is planned as a tall industrial volume used vertically as well as across the floor rather than as generic covered area.

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. Plan the exit as carefully as the entrance; buildings are emptied under more time pressure than they are filled.

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 high bay industrial planning genuinely needs the extra clear height or only the floor area.

Ventilation across 12,000 square feet at this height: process air is a design requirement rather than general comfort ventilation.

The servicing pattern this shell could equally be operated under is a single serviced work floor operated by one occupier: there is no services strip, so the panel, the air line and the welfare corner sit against the working floor and are worked around. Dividing the 12,000 sq ft by the 32 by 50 ft high bay gives roughly 4 positions before circulation is deducted a second time for cross movement. Whether the plan keeps 4 or drops to 2 comes back to the question this footprint is really answering: which parts of this building genuinely need the height, and what is placed under the parts that do not?

Depth arithmetic leaves a working end zone here. 4,600 square feet sits past the last row, which is why 100x120 tends to be planned with a low-level fitted band — offices, stores, plant — with usable volume above it inside the same shell designed in rather than added later. The plan should survive the day the largest item the operation owns has to come inside.

The 4 feet of spare width runs the whole 120-foot length — 480 square feet of wall strip. It earns its keep as shelving, staging or a walking route, not as another high bay. A leftover strip earns its place only when something is deliberately put in it; otherwise it is circulation with a nicer name.

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 2 high bays across rather than 2, 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 a tall industrial volume used vertically as well as across the floor that matters where high bay industrial planning sits, because shortening the 100 ft run to serve it lengthens every trip along the 120 ft dimension. Waste, recycling and returns need a defined position or they occupy the nearest clear floor permanently. That movement pattern, not the 12,000-square-foot total, is what decides whether the leftover 46 feet is useful here.

The columns win at this footprint: 24-foot nominal bays against a 32-foot module means every layout decision starts from where the frames fall. The corner nobody plans for is the one that fills first, which is an argument for planning it.

A single row means nothing is trapped: every position faces the opening directly, which is this footprint's advantage over a deeper building of the same width. What the building holds in its busiest week is the honest brief; the rest of the year is slack.

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 170 adds a 3th run of high bays — useful if the constraint is high bays rather than the 20 ft already spare at the far end.

Configured as a tall industrial volume used vertically as well as across the floor, 100x120 is judged on whether the 3 high bays it holds match the operation, and on whether the 4 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?
• What direction does material flow, and are the openings at the right ends?
• Is overhead handling planned, and has that been raised as an engineering requirement?

The 100-foot gable can carry 3 openings, one per high bay, with 4 feet of wall left for piers between and beside them — the arrangement that keeps each position independently reachable. Interior divisions are the last decision that should be fixed, because they are the first one that usually changes.

Openings serve the floor level; the height is served by what is inside. A tall door is only worth its cost when something tall actually passes through it, which is a narrower case than it first appears.

• 60x80 moves the count from 3 to 2 high bays (2 across by 1 deep), which is the reason to choose between them.
• 40x120 moves the count from 3 to 1 high bays (1 across by 1 deep), which is the reason to choose between them.
• 50x100 moves the count from 3 to 4 high bays (2 across by 2 deep), which is the reason to choose between them.

Because this footprint is planned as a tall industrial volume used vertically as well as across the floor, the useful next reads are different from the ones a differently shaped industrial building suggests: high bay industrial planning, worked volume, mezzanine infill.