50x100 Steel Office Building

This page is ordered around the enclosed space that supports the open floor, because focus and call rooms are what make open desking usable and are the first thing cut.

The footprint holds 28 private offices — 4 across by 7 deep — and the remaining 2 feet is marginal: there is no support core, so shared functions sit in the corridor and every use of them is heard through two doors.

Efficiency is the useful number here: 179 square feet of enclosed floor per private office, against a 143-square-foot module. That leaves working slack around each position. Storage expands until it meets a wall, so give it a wall on purpose.

A 50 by 100 footprint is a clearly directional plan: 5,000 sq ft enclosed by 300 ft of wall, at a 2:1 length-to-width proportion. Along its 100 ft dimension it takes 7 runs of private offices at 13 ft, leaving 9 ft over — the 9 ft is where the argument about this size actually happens. A cellular plan trades floor for privacy, and the trade is measured in corridor. The planning question is the ratio: rooms deep enough to work in, off a corridor short enough not to consume the floor. Heating and cooling zoning follows occupancy patterns rather than the floor plate.

This footprint is planned as an office of individual rooms, planned around privacy and corridors. Compared with a 50 by 80 of the same width, the extra depth here adds run rather than reach: it buys about 7 private offices in line, and every position past the second is retrieved by moving what stands in front of it. Spent as a square 71 by 71 instead, the same 5,000 sq ft would stand 5 private offices 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. At this size the building becomes a shared resource, and shared resources need a written rule for who parks where and which door is kept clear. Occupants stay in their rooms and meet in shared ones. Confidentiality is often the reason for the plan, which makes acoustic separation a requirement rather than a comfort. A building's parking and arrival sequence are part of the first impression the office makes.

The work pattern this floor could equally be planned around is an office visitors come to, planned around arrival and meeting: there is no reception depth, so visitors arrive directly into the work floor and every arrival interrupts it. Dividing the 5,000 sq ft by the 11 by 13 ft private office gives roughly 21 positions before circulation is deducted a second time for cross movement. Whether the plan keeps 21 or drops to 14 comes back to the question this footprint is really answering: how much of this floor becomes corridor once every room needs its own door?

There is no end zone at this footprint. 2 feet is circulation slack, not floor area with a purpose, and there is no support core, so shared functions sit in the corridor and every use of them is heard through two doors. Judge the plan by what has to happen on the worst day of the year, not on an average one.

Spare width is the more valuable of the two leftovers here: a continuous 6-foot strip beats the same area stranded at the end of the run, because it touches every position along the way. Rows that cannot be entered independently end up used as one long space.

Compared with a 50 by 80 of the same width, the extra depth here adds run rather than reach: it buys about 7 private offices in line, and every position past the second is retrieved by moving what stands in front of it. Spent as a square 71 by 71 instead, the same 5,000 sq ft would stand 5 private offices 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. At this size the building becomes a shared resource, and shared resources need a written rule for who parks where and which door is kept clear. Occupants stay in their rooms and meet in shared ones. Confidentiality is often the reason for the plan, which makes acoustic separation a requirement rather than a comfort. A building's parking and arrival sequence are part of the first impression the office makes. That movement pattern, not the 5,000-square-foot total, is what decides whether the leftover 2 feet is useful here.

Nominal bay division computes to 4 bays at about 25 feet, wider than the 11-foot module — so a position can sit inside a bay without a frame line splitting it. Circulation width is the first thing surrendered under pressure and the first thing missed afterwards.

With 7 rows deep, the rear row is behind the front one. Without a route past it, those private offices become storage positions rather than working ones — the real cost of depth at this width. Two feet of spare width reads as nothing on a plan and as a great deal when a machine is being turned.

Extension is cheapest along the 100 ft dimension, where each added bay repeats work already framed; widening past 50 ft is a different frame rather than a longer one. Growing to 50 by 113 adds a 8th run of private offices — useful if the constraint is private offices rather than the 9 ft already spare at the far end.

Configured as an office of individual rooms, planned around privacy and corridors, 50x100 is judged on whether the 28 private offices it holds match the operation, and on whether the 6 feet of spare width leaves the route this mode depends on.

• Does the work need three lanes and a working lane, or two lanes with an interior work hall between them, or does it need a second lane that this 50-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 stored configuration carries a 16-foot eave and computes to 22.3 feet at the ridge on a 3:12 pitch — a 6.3-foot rise across 50 feet. Height is therefore not uniform, and the sidewall is the constraint. The plan is only as good as the route into it, which is a site question rather than a building one.

Height on a 50 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 5,000 sq ft affects every bay along the 100 ft dimension, so the test is whether cellular office plan genuinely needs the extra clear height or only the floor area.

Ventilation across 5,000 square feet at this height: continuous occupancy at desk density makes air handling a core system rather than an accessory.

The 50-foot gable can carry 4 openings, one per private office, with 6 feet of wall left for piers between and beside them — the arrangement that keeps each position independently reachable. Whoever operates the building daily should read the plan before it is frozen, because they know where the pinch points are.

One entrance, with the corridor legible from it — a cellular plan that cannot be navigated by a visitor needs signage forever.

The estimate at 50x100 moves with four computed quantities: 5,000 square feet of floor, 300 feet of perimeter, 4,800 square feet of wall and 5,154 square feet of roof. Everything else is site and specification. Daylight placement changes how a floor is used far more than its cost suggests.

Partitions, doors, acoustic treatment and separate services per room make this the most expensive fit-out per square foot of the office types.

• 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

• 40x50 moves the count from 28 to 9 private offices (3 across by 3 deep), which is the reason to choose between them.
• 30x70 moves the count from 28 to 8 private offices (2 across by 4 deep), which is the reason to choose between them.
• 36x60 moves the count from 28 to 9 private offices (3 across by 3 deep), which is the reason to choose between them.

Because this footprint is planned as an office of individual rooms, planned around privacy and corridors, the useful next reads are different from the ones a differently shaped steel office building suggests: cellular office plan, corridor efficiency, acoustic separation.