50x100 Barndominium

This page is ordered around the floor itself, because at 50x100 the 5,000 sq ft available decides what a barndominium can hold before any other consideration applies.

The footprint holds 12 bands — 3 across by 4 deep — and leaves 16 feet of depth for a middle band holding utility, storage and circulation, which is what keeps the living and working sides from touching.

Commitment first: 69% of the 5,000 square feet goes to bands at 288 square feet each, and 1,000 square feet survives as edge strip. A footprint is worth its own decision when that split lands where the work does. Fire separation, egress and occupancy are determined for the specific building and can reshape this plan entirely.

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 5 runs of bands at 18 ft, leaving 10 ft over — the 10 ft is where the argument about this size actually happens. Once the span is wide enough, separation stops being a line and becomes a zone. A middle band of utility, storage and circulation gives the dwelling a genuine buffer from the working side — acoustically, thermally and in daily use — which a single partition never does. The boundary between living and working space is the decision the whole building is organised around.

This footprint is planned as a wide plan where separation is achieved by a buffer zone rather than a single wall. Compared with a 50 by 80 of the same width, the extra depth here adds run rather than reach: it buys about 5 bands 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 3 bands 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. 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. The two routines never share a route. The buffer takes the crossings, which is why the laundry, the boot room and the plant tend to end up there. Where the residential entrance sits relative to the working apron decides how the building feels to arrive at.

50 ft across takes 3 bands and leaves 2 ft. Over 100 ft of run that slack becomes a continuous side aisle rather than 4 separate gaps.

100 ft divides exactly into 10 bays at 10 ft. Over 5,000 sq ft a single 10-ft grid is the difference between a plan and an accumulation.

100 ft is deep enough for 4 ranks and a zone behind them. 5,000 sq ft needs a stated route through it; without one the middle silts up.

16 ft carries a genuine second level: 15 ft deep across the 50-ft width is 750 sq ft more floor. Framing for it now is a drawing change; adding it to a finished frame is a structural one.

The 50-ft gable clears about 42 ft after corner framing — 2 module-width openings abreast. At 4 ranks deep the useful pattern is end in, side out, using the 100-ft wall's 4 possible positions.

16 ft survives at the end of the run — 800 sq ft across the full width. That is a zone to name before the frame is ordered, not a leftover to discover after it.

The living-and-working balance this footprint could equally be planned around is a dwelling with a working bay attached rather than a shop with rooms in it: there is no buffer between the working bay and the living rooms, so the shop door opens straight into occupied space. Dividing the 5,000 sq ft by the 16 by 18 ft band gives roughly 10 positions before circulation is deducted a second time for cross movement. Whether the plan keeps 10 or drops to 5 comes back to the question this footprint is really answering: is the space between the two sides doing useful work, or is it just a wall?

The 16-foot leftover depth is 800 square feet across the full width — deep enough to plan deliberately, and at this footprint it goes to a middle band holding utility, storage and circulation, which is what keeps the living and working sides from touching. The mezzanine that is added afterwards is the change order that reprices the frame.

Width is fully committed at 50x100. With 2 feet spare, wall storage and passing room compete with the bands directly. Storage expands until it meets a wall, so give it a wall on purpose.

Compared with a 50 by 80 of the same width, the extra depth here adds run rather than reach: it buys about 5 bands 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 3 bands 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. 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. The two routines never share a route. The buffer takes the crossings, which is why the laundry, the boot room and the plant tend to end up there. Where the residential entrance sits relative to the working apron decides how the building feels to arrive at. That movement pattern, not the 5,000-square-foot total, is what decides whether the leftover 16 feet is useful here.

Nominal bay division computes to 4 bays at about 25 feet, wider than the 16-foot module — so a position can sit inside a bay without a frame line splitting it. Judge the plan by what has to happen on the worst day of the year, not on an average one.

With 4 rows deep, the rear row is behind the front one. Without a route past it, those bands become storage positions rather than working ones — the real cost of depth at this width. Rows that cannot be entered independently end up used as one long space.

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 118 adds a 6th run of bands — useful if the constraint is bands rather than the 10 ft already spare at the far end.

Configured as a wide plan where separation is achieved by a buffer zone rather than a single wall, 50x100 is judged on whether the 12 bands it holds match the operation, and on whether the 2 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?
• Where does the dividing wall sit, and what does the working half lose when it moves?
• Is there a loft, and has the frame been planned for it rather than around it?

At 50 feet the gable will not comfortably take one opening per band: 3 positions with 2 feet spare leaves too little wall for piers. A single wider opening, or a sidewall opening, is the workable route. Two feet of spare width reads as nothing on a plan and as a great deal when a machine is being turned.

Each band can have its own external access, and the wide span usually allows the working doors and the residential entrance to sit on different elevations entirely.

Span drives headroom at 50x100: 50 feet of width on a 3:12 pitch puts 22.3 feet over the middle and 16 feet at the walls, so where a tall item stands matters as much as how tall it is. Circulation width is the first thing surrendered under pressure and the first thing missed afterwards.

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 wide barndominium plan genuinely needs the extra clear height or only the floor area.

Ventilation across 5,000 square feet at this height: the working half generates air the living half should never receive, so the boundary handles air as well as sound.

• 40x50 moves the count from 12 to 2 bands (2 across by 1 deep), which is the reason to choose between them.
• 30x70 moves the count from 12 to 8 bands (2 across by 4 deep), which is the reason to choose between them.
• 36x60 moves the count from 12 to 9 bands (3 across by 3 deep), which is the reason to choose between them.

Because this footprint is planned as a wide plan where separation is achieved by a buffer zone rather than a single wall, the useful next reads are different from the ones a differently shaped barndominium suggests: wide barndominium plan, buffer band between living and shop, three-band layout.