For the most part, obtaining a building permit for a pole barn, or a waiver of the need to obtain one, is very easy. In my humble opinion, far too easy. The reality is… code enforcement agencies generally do NOT require engineering design documents for pole buildings.
Pole buildings are highly stressed, structurally indeterminate structures which mostly rely on wall coverings (wood or metal sheathing) for stability. Even a simple building has a minimum of ten connections and structural elements which require structural analysis to ensure building code compliance.
Among the elements which should be checked are the building columns (posts), the post embedment, the post footing, connection of the trusses to the columns, roof purlins, wall girts, roof and wall sheathing, and the lateral bracing system.
The engineering design analysis of a pole building is closer to an airplane, than a stud framed building. In our case, even a simple, rectangular pole building permit submittal requires seven or eight 24” x 36” blueprint sheets as well as over 100 pages of calculations.
There is no prescriptive building code for pole buildings, much due to the wide range of possible design solutions, as well as the numerous types of buildings which can be built using post frame. Unlike stick frame buildings, where studs are placed every 16 or 24 inches, pole barns can have structural columns anywhere from four to even 20 feet on center! Building Officials and Plans Examiners are hired to ensure building code compliance and, thereby, public health, safety and welfare. While it seems reasonable for engineering documentation to be required for pole buildings, more often than not, this is not the case. In reality, more than a few code enforcement officers and Building Departments are assisting unknowing clients to circumvent the building code.
Some jurisdictions actually hand out design documents whereby non-compliant, unsafe buildings are allowed to be permitted and constructed! Under structural analysis, these “prescriptive” requirements include overstresses of two, three or even four times the design loads. If an engineer would provide designs such as these, the engineer would lose his (or her) registration!
Non-engineered buildings fall down at an alarming rate. Even a little sprinkle of snow causes failures such as buildings collapsing under less than half the local design snow load. Supposedly this is deemed to be an “Act of God”. In reality, it is building contractors and Building Departments doing less than due diligence.
I heard a story recently about a woman whose building had blown over in a little puff of breeze the day after the contractor left the building site. The woman owned two acres and a llama. The Building Department had done her a favor and given her an Ag Permit. The Ag Permit saved her money and kept her from having to comply with the Building Code. It also kept her out of the “clutches” of the engineers. Some favor. She had absolutely no recourse. The disheartening thing is the collapse could have been prevented by the installation of a few pieces of pressure treated wood the contractor left behind in the scrap pile.
Nearly every state does not enforce the Building Code for all pole buildings. Much of the thought process is, “It’s just a pole building, who cares?” We should all care. When buildings fail, insurance companies pay and premiums go up. I care because under designed non-engineered building failures make it tougher on those of us who do use prudent engineering designs.
In most cases, engineering adds little or nothing to the cost of the overall structures. Engineers are able to eliminate redundant components, which add nothing but take dollars out of the building owner’s pocket.
If you are told your new building is permit or code exempt, a permit will be issued without a thorough structural review, or no engineered drawings are required, you should question as to why? In the end, the life you save…just may be your own.
