80x100 Steel Office Building

Quantities, not prices, are publishable here: roof cladding runs 8,433 square feet — 5% above the 8,000-square-foot floor at a 4:12 pitch — with 148.1 cubic yards of nominal slab beneath it. Rows that cannot be entered independently end up used as one long space.

Proportion drives cost here as much as size does: 360 ft of wall around 8,000 sq ft is 0.045 ft of wall per enclosed square foot, and a squarer plan of the same area would carry less. What moves the figure further on a an open working floor with enclosed space for the work that needs it is the fit-out open plan office floor implies, along with framed openings and the height chosen for the 80 ft span.

• interior partitions, ceilings and finishes across the whole floor
• the service core with restrooms and kitchen
• air handling for continuous occupancy
• small-power and data distribution density

This page is ordered around the door between the quiet side and the working side, because that interface is what a combined building actually has to solve.

The footprint holds 25 team zones — 5 across by 5 deep — and leaves 11 feet of depth for focus and call rooms at the floor's edge, so concentrated work has somewhere to go without booking a meeting room.

Commitment first: 70% of the 8,000 square feet goes to team zones at 224 square feet each, and 1,880 square feet survives as edge strip. A footprint is worth its own decision when that split lands where the work does. Set the openings before the interior, because the openings cannot move and the interior can.

A 80 by 100 footprint is a mildly directional plan: 8,000 sq ft enclosed by 360 ft of wall, at a 1.3:1 length-to-width proportion. Along its 100 ft dimension it takes 6 runs of team zones at 16 ft, leaving 4 ft over — the 4 ft is where the argument about this size actually happens. An open floor works when the enclosed space that supports it exists. Focus rooms, call booths and a quiet edge are not extras; they are the parts that make the open area usable, and they are what get cut first. Occupant load, egress and accessibility are determined for the specific project by the design professional and the authority having jurisdiction.

This footprint is planned as an open working floor with enclosed space for the work that needs it. Spent as a square 89 by 89 instead, the same 8,000 sq ft would stand 5 team zones across rather than 5, and would trade this plan's length for parallel access. That is the width-against-depth decision this footprint has already made. Compared with a 80 by 80 of the same width, the extra depth here adds run rather than reach: it buys about 6 team zones in line, and every position past the second is retrieved by moving what stands in front of it. 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 floor is occupied all day at varying densities, so circulation and acoustic separation matter more than desk count. Heating and cooling zoning follows occupancy patterns rather than the floor plate.

Nominal bay division computes to 4 bays at about 25 feet, wider than the 14-foot module — so a position can sit inside a bay without a frame line splitting it. Fire separation, egress and occupancy are determined for the specific building and can reshape this plan entirely.

With 5 rows deep, the rear row is behind the front one. Without a route past it, those team zones become storage positions rather than working ones — the real cost of depth at this width. The mezzanine that is added afterwards is the change order that reprices the frame.

Density increases before area does, which makes the initial provision of enclosed rooms a decision about the floor's future rather than its present.

Configured as an open working floor with enclosed space for the work that needs it, 80x100 is judged on whether the 25 team zones it holds match the operation, and on whether the 10 feet of spare width leaves the route this mode depends on.

• Does the work need racking or work zones on both sides with a full vehicle lane down the middle, or does it need a second lane that this 80-foot span cannot give?
• Is the 100-foot length being bought for depth, or for the repeated bays — eight to ten repeated bays, which makes the layout a scheduling problem as much as a spatial one?
• What finished ceiling height do you want, and what service zone sits above it?
• Where does the service core go, and does the desk plan work around it?

The 80-foot gable can carry 5 openings, one per team zone, with 10 feet of wall left for piers between and beside them — the arrangement that keeps each position independently reachable. Judge the plan by what has to happen on the worst day of the year, not on an average one.

One main entrance plus daylight distribution, which is a window and depth question rather than a door one.

The work pattern this floor could equally be planned around is office space attached to a working or storage area in one building: there is no transition zone, so the working side's dirt, noise and traffic arrive in the office through a single door. Dividing the 8,000 sq ft by the 14 by 16 ft team zone gives roughly 30 positions before circulation is deducted a second time for cross movement. Whether the plan keeps 30 or drops to 24 comes back to the question this footprint is really answering: where does someone go to concentrate, and where do they go to take a call?

Because 11 feet clears the 10 feet this platform treats as usable, the end of the run is a room rather than a gap: 880 square feet for focus and call rooms at the floor's edge, so concentrated work has somewhere to go without booking a meeting room. Where the building sits on the site changes how much of this floor is genuinely reachable.

Spare width is the more valuable of the two leftovers here: a continuous 10-foot strip beats the same area stranded at the end of the run, because it touches every position along the way. Snow, wind and site exposure change what this shape costs to build long before the interior plan does.

Spent as a square 89 by 89 instead, the same 8,000 sq ft would stand 5 team zones across rather than 5, and would trade this plan's length for parallel access. That is the width-against-depth decision this footprint has already made. Compared with a 80 by 80 of the same width, the extra depth here adds run rather than reach: it buys about 6 team zones in line, and every position past the second is retrieved by moving what stands in front of it. 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 floor is occupied all day at varying densities, so circulation and acoustic separation matter more than desk count. Heating and cooling zoning follows occupancy patterns rather than the floor plate. That movement pattern, not the 8,000-square-foot total, is what decides whether the leftover 11 feet is useful here.

Span drives headroom at 80x100: 80 feet of width on a 4:12 pitch puts 33.3 feet over the middle and 20 feet at the walls, so where a tall item stands matters as much as how tall it is. Storage expands until it meets a wall, so give it a wall on purpose.

Height on a 80 ft span is a separate decision from the 100 ft length, and it is the span that sets the frame's behavior. Raising the eave over 8,000 sq ft affects every bay along the 100 ft dimension, so the test is whether open plan office floor genuinely needs the extra clear height or only the floor area.

Ventilation across 8,000 square feet at this height: continuous occupancy at desk density makes air handling a core system rather than an accessory.

• 40x80 moves the count from 25 to 8 team zones (2 across by 4 deep), which is the reason to choose between them.
• 60x60 moves the count from 25 to 12 team zones (4 across by 3 deep), which is the reason to choose between them.
• 50x80 moves the count from 25 to 12 team zones (3 across by 4 deep), which is the reason to choose between them.

Because this footprint is planned as an open working floor with enclosed space for the work that needs it, the useful next reads are different from the ones a differently shaped steel office building suggests: open plan office floor, focus and call rooms, daylight distribution.