Post frame construction is touted for its durability, sustainability, and cost-savings.
Perhaps, the building system’s biggest advantage is design flexibility. It’s the very reason why architects, designers, and engineers favor this construction method over others.
Every day, pole barns are going up in rural and suburban areas. Take a look for yourself when running errands in town or traveling across the state.
You’ll see agricultural, commercial, residential, and equine buildings of all shapes and sizes. It makes you wonder, “How does one determine his/her pole barn dimensions?”
In this article, we discuss the five essential questions you should ask yourself when determining pole barn height.
As for length and width, we recommend reading our blog over popular building sizes.
Pole barn height is based on the following factors: primary use, structural integrity, building features, location, and codes.
In other words, there is no black and white answer. Therefore, selecting a post frame builder with in-house engineers is crucial.
Why? Because they’ll work closely with salespeople and outside parties to achieve desired height while meeting design requirements.
For instance, hardworking farmers need a taller tractor & implement storage building to accommodate large doors and heavy machinery. It’s convenient to store and move large implements under one roof.
Warehouses need higher ceilings for easier access to assembly lines, deliveries, equipment, and trucks.
Avid outdoorsmen need ample clearance when housing their boat and camper in the off-season.
Recently, pole barn construction has become a popular housing option. Post frame homes can be one- or two-story depending on the homeowners’ needs.
Equine enthusiasts can add dimension to their horse barns, whether it be for an observation lounge or hay storage.
Don’t forget to consider future use. We always recommend adding extra square footage. Why? Because no one has ever said, “My pole barn is too big!”
Unfortunately, some customers don’t think that far in advance. Eventually, they run out of space and have to add-on to their existing post frame structure.
Taking the time to contemplate future purchases (big or small) will help you save money in the long run. Not to mention, it’ll spare you from buyer’s remorse and growing pains.
Any post frame building, regardless of size and location, must be designed to resist vertical and lateral loads safely.
Lateral loads act in a direction parallel to the ground (e.g., earthquakes and high winds). These forces can work in any direction. Therefore, the pole barn must be designed to withstand loads, both parallel and perpendicular to any wall.
All structural loads must be able to pass from the areas in which the load is applied. This transfer of forces through the post frame structure is called the load path. A continuous load path transfers all vertical and lateral loads from one building component to another until they reach the ground.
If the load path flows continuously without interruption, there will be no structural damage. However, one break in the course can cause significant damage.
One “weak link” is all it takes to compromise the structural integrity of your pole barn. Therefore, each building component must be strong enough to carry out these anticipated design loads.
While the building system consists of multiple parts, we detail specific areas affected by pole barn height.
The term “laminated column” refers to two or more layers of dimensional lumber that has been mechanically laminated with nails. These posts are made from 2x6 or 2x8 lumber.
In taller buildings, you can upgrade the columns to 2x12 lumber. Or, you can use engineered wood, such as Parallam® PSL Columns.
This manufacturing process uses veneer strands, which allow for higher load capacity. Because it’s made with conjoined veneers, Parallam is available in specialty lengths that exceed conventional lumber.
If engineered wood is incompatible with your building design, you can opt for a hybrid system. This approach consists of steel columns and wood trusses. It’s used in pole barns where engineered lumber isn’t a viable option.
Please note that “over-sized” columns won’t necessarily make your post frame building stronger. Why? Because the diaphragm carries the majority of wind loads.
In post frame construction, buildings can resist extreme lateral loads through the diaphragm design.
A diaphragm is a flat structural unit acting like a deep, narrow beam. It is usually applied to pole barn floors and roofs.
Moreover, a shear wall is a vertical diagram. It provides support for the floor and roof diaphragms transmitting forces into the foundation.
A structural diaphragm results when a series of diaphragms are properly tied together to form a unit.
Most sheathed elements (when using good construction methods) add considerable strength to the structure.
Without the diaphragm or protective steel, columns will bear a full load of your pole barn. Open-sided buildings are a prime example.
As building height increases, so does the need for a structural diaphragm.
The design load is based on wind speed and building codes obtained from the American Society of Civil Engineers Standard (ASCE 7-10). This publication helps engineers determine load requirements essential to their practice.
Wind speed increases with height above ground. Consequently, taller pole barns are exposed to greater pressures.
Furthermore, engineers account for the following influential factors when calculating your post frame building’s wind load:
Regardless of pole barn height, wind load is a critical aspect of the building design.
For instance, you’d like to have an 18’ overhead door for quick and easy access to your farm shop. Typically, 2’ is added for sufficient building clearance.
If you prefer a wider opening or full building clearance, then a sliding door will work best for your operation. This dooring option will allow you to have an approximate 18’ opening with an 18’ eave.
Another building feature that influences pole barn height is porches, which are used to shelter people from the elements as they access the structure via a walk door.
Porches are also a comfortable place to sit and enjoy the outdoors. On a lazy evening, you can sit in a wooden rocking chair with a cold glass of sweet tea and watch your children (or grandchildren) ride ATVs around the yard.
For a “cozy” aesthetic, your porch shouldn’t be too tall. 7’ to 8’ of building clearance is ideal. You may have to adjust your pole barn height accordingly.
Are you interested in adding a lean-to? Please note that the door size on the end-wall or side-wall will affect the height of the lean-to and post frame building.
In some situations, the building location may impact your building design.
For instance, you’re outgrowing your current space and looking at potential sites to expand your commercial business.
Some properties have restrictions (e.g., setbacks, easements, parking lots, and retention ponds) that limit the building size.
As a result, you want to increase the height via stories for more usable square footage.
Although it may be a feasible option, we recommend opting for a larger one-story building (if possible). Often, it’s more economical to build a larger one-story than a smaller two-story project.
Post frame structures should be code compliant, especially commercial buildings.
For local construction codes, please contact your local building official or authority having jurisdiction (AHJ).
Construction type is one of the primary indicators of allowable height (or the number of stories) by the International Building Code.
All buildings are assigned a construction type, which determines the building components’ level of fire resistance.
At FBi Buildings, our standard building is a Type 5B. This classification means our pole barns are constructed with any materials permitted by the code.
Unsurprisingly, the other factor is building use. The code uses occupancy groups to determine the allowable height. There are ten categories: A, B, E, F, H, I, M, R, S, and U. For example, a horse barn would fall under the Group U occupancy.
Using these two variables, you can determine the allowable height by following the corresponding code tables.
Customarily, Type 5B construction is limited to one story. However, the code does provide some considerations that allow us to gain an extra story.
In these situations, we recommend working with a post frame builder and their in-house engineers. They work closely with salespeople and outside parties to meet design requirements and customers’ needs/wants.
While we can’t tell you how tall to make your post frame building, we can provide solid talking points to discuss with your professional builder and their team.
Do you already have a certain height in mind? Visualize your future post frame building with our 3D design tool. Save, print, or email your final plan to family and friends.
If not, you can browse through our pole barn gallery and FREE floor plans for inspiration.
Are you ready for a quote? Share your design with us, and a member of our sales team will give you a call to begin the estimating process.
We also recommend that you check out The Ultimate Guide to Building a Pole Barn. This guide will help you navigate the steps you need to take before and during construction to insure your project gets done on time and under budget.
Have more questions about pole barn height not covered in this article? Please contact FBi Buildings at 1.800.552.2981 or click here to email us. If you’re ready to get a price, click here to request a quote and a member of our sales team will call you.