80x120 Pole Barn

This page is ordered around which part of the building is meant to be comfortable, because treating the whole envelope as one condition is what leaves it unused in January.

The footprint holds 20 working bays — 5 across by 4 deep — and leaves 16 feet of depth for a lined and lit corner that stays usable in cold weather while the rest of the building remains unheated.

What distinguishes 80x120 is depth behaviour: 4 rows along 120 feet after 8 feet of circulation, with 16 feet unaccounted for at the end of the run. A building that cannot be reversed out of is a building that gets used in one direction only.

A 80 by 120 footprint is a clearly directional plan: 9,600 sq ft enclosed by 400 ft of wall, at a 1.5:1 length-to-width proportion. Along its 120 ft dimension it takes 5 runs of working bays at 24 ft, leaving 0 ft over — the 0 ft is where the argument about this size actually happens. Taken purely as arithmetic, 80 by 120 gives 5 working bays across the 80 ft dimension once 8 ft is reserved for movement, and 5 deep along the 120 ft dimension. Run as a a fully enclosed post-frame building serving mixed daily use, 2 ft across is below the 10 ft this use needs to be worth planning, so there is no lined corner, so the whole building shares one temperature and cold-weather work happens elsewhere Ground contact at the post base is a durability question resolved by the specified detail for the site.

This footprint is planned as a fully enclosed post-frame building serving mixed daily use. Spent as a square 98 by 98 instead, the same 9,600 sq ft would stand 6 working bays 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 90 of the same width, the extra depth here adds run rather than reach: it buys about 5 working bays 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. Daily use mixes vehicles, storage and work, and the plan works when the noisy, dirty and warm activities each have a bay rather than sharing one. Lighting placement follows the work rather than the truss layout.

Read this page as a construction-form page, not a use page. Pole barn is a construction-form category on this platform: it describes the post-frame approach, where posts carry the roof and the walls enclose between them, and the uses it serves — agricultural, garage, workshop, storage — are applications of that form rather than definitions of it. The question it answers is how a 80x120 footprint behaves when it is built this way.

The use this post-frame shell could equally be bought for is a single-bay shelter where the frame and the room are the same thing: there is no strip between posts and wall, so stored items stand in the bay itself and the bay stops being clear. Bulk and vehicle space in the main bays, and a defined corner or end bay for the work that needs light and warmth. Attempting to condition the whole volume rarely survives the first heating season.

Depth arithmetic leaves a working end zone here. 1,280 square feet sits past the last row, which is why 80x120 tends to be planned with a lined and lit corner that stays usable in cold weather while the rest of the building remains unheated designed in rather than added later. Noise from this floor reaches the office, the neighbours and the yard, and separation is a plan decision.

The 10 feet of spare width runs the whole 120-foot length — 1,200 square feet of wall strip. It earns its keep as shelving, staging or a walking route, not as another working bay. Temperature swing on a steel shell drives condensation decisions that outrank most layout preferences.

Spent as a square 98 by 98 instead, the same 9,600 sq ft would stand 6 working bays 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 90 of the same width, the extra depth here adds run rather than reach: it buys about 5 working bays 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. Daily use mixes vehicles, storage and work, and the plan works when the noisy, dirty and warm activities each have a bay rather than sharing one. Lighting placement follows the work rather than the truss layout. That movement pattern, not the 9,600-square-foot total, is what decides whether the leftover 16 feet is useful here.

The 80-ft span holds 5 working bays plus 10 ft — most of another position. With 4 ranks behind each other the width sets retrieval order: what goes in first comes out last.

Nothing lands in the middle of a 80-ft clear width. The 4 ranks along the 120-ft length are the only fixed geometry the plan has; every other division is furniture.

120 ft divides exactly into 10 bays at 12 ft. Over 9,600 sq ft a single 12-ft grid is the difference between a plan and an accumulation.

A 22-ft eave puts 275,040 cu ft inside and makes the upper half a planning question in its own right. The stair comes out of the 10 ft of spare width rather than out of the working floor.

120 ft is deep enough for 4 ranks and a zone behind them. Past 9,600 sq ft the plan needs zones with names, because nothing about the shell suggests them.

The 10 ft left across the width is most of another working bay without being one. Given a purpose it becomes a lined and lit corner that stays usable in cold weather while the rest of the building remains unheated; left undefined it becomes the strip everything ends up in.

Nominal bay division computes to 5 bays at about 24 feet, wider than the 14-foot module — so a position can sit inside a bay without a frame line splitting it. The count of working positions, not the headline area, is the figure that survives contact with the operation.

Two-plus rows change the access question entirely. Every rear position at 80x120 needs either its own opening or an aisle, and 10 feet of spare width is what that aisle has to come from. Access, not area, is what makes a plan feel small once it is in use.

Bays add in line; the lined corner rarely moves, so placing it at an end keeps the extension direction open.

Configured as a fully enclosed post-frame building serving mixed daily use, 80x120 is judged on whether the 20 working bays 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 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?
• Does the intended layout tolerate interior posts, or does it genuinely need a clear span?
• Where do the openings fall relative to the post lines, and does any opening have to bridge one?

One opening per position works on this gable: 5 across 80 feet, with 10 feet of wall to distribute as piers. Splitting that margin evenly is what keeps the elevation buildable. Where the building sits on the site changes how much of this floor is genuinely reachable.

The 80 ft ends and the 120 ft sides offer very different opening budgets: 80 ft of end wall has room for one wide opening or two modest ones, while 120 ft of side wall can carry several without the openings competing. On this plan the deciding factor is whether enclosed post frame building or lined working corner should be the first thing reached from the door.

Loading happens bay by bay: what can be brought in at one opening and set down in that bay is the practical unit, not the length of the wall.

Across a 80-foot span the 4:12 pitch adds 13.3 feet between eave and ridge. The centreline measures 35.3 feet; anything parked or stacked near a wall lives with the 22-foot eave. Set the openings before the interior, because the openings cannot move and the interior can.

Height serves storage above the working level and the equipment that enters. Post frame makes it inexpensive, which is why it is usually worth taking.

Ventilation across 9,600 square feet at this height: post-frame buildings are frequently left partly open or lightly enclosed, so natural cross and ridge airflow does much of the work and enclosure level is the variable to settle first.

• 50x80 moves the count from 20 to 16 working bays (4 across by 4 deep), which is the reason to choose between them.
• 40x100 moves the count from 20 to 8 working bays (2 across by 4 deep), which is the reason to choose between them.
• 60x80 moves the count from 20 to 12 working bays (4 across by 3 deep), which is the reason to choose between them.

Because this footprint is planned as a fully enclosed post-frame building serving mixed daily use, the useful next reads are different from the ones a differently shaped pole barn suggests: enclosed post frame building, lined working corner, mixed daily use.

Quantities, not prices, are publishable here: roof cladding runs 10,119 square feet — 5% above the 9,600-square-foot floor at a 4:12 pitch — with 177.8 cubic yards of nominal slab beneath it. Snow, wind and site exposure change what this shape costs to build long before the interior plan does.

Proportion drives cost here as much as size does: 400 ft of wall around 9,600 sq ft is 0.042 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 a fully enclosed post-frame building serving mixed daily use is the fit-out enclosed post frame building implies, along with framed openings and the height chosen for the 80 ft span.

• how many sides are enclosed, and whether any stay open
• the bay rhythm relative to the openings and layout wanted
• the ground interface and site conditions at the post positions
• whether lean-tos or additions are planned onto the same rhythm
• later lining or insulation of the wall assembly between posts