In a misguided effort to make things “easier” for potential building owners and builders, some Building Departments have prescriptive requirements for non-engineered pole buildings.
This means if someone walks in the Building Department door and wants to construct a pole building, as long as the building owner (or builder) agrees to build to match the prescriptive requirements, they will be issued a structural permit. This is, of course, with the caveat of being able to meet the requirements of other departments, such as Planning.
WHY IS THIS BAD?
Prescriptive requirements are often based upon, “the way things have always been done”, rather than having a basis in the sound fundamentals of structural design. Every three years a new version of the Building Code is published, sometimes with sweeping changes in structural design. Many highly qualified design professionals, including many engineers, are involved in revisions of the Building Code.
A classic example of this came when the International Building Codes were first adopted in 2000. Prior Codes did not have deflection criteria for wall members in those cases where the members did not support a rigid finish (like plaster or gypsum board). The new Code limits the deflection in all cases. In order to meet the new requirements, in many cases, pole building wall girts can no longer be installed “flat” on the outside of the wall columns.
Many times materials are included in the prescriptive requirements which do nothing but cause more work for whoever is doing the actual construction, as well as using materials which either are not necessary, or are larger than what an engineer would have specified.
On occasion, these prescriptive requirements do not actually meet the Building Codes. In my spare time, I have challenged more than one of them and gotten Building Departments to make changes. The prescriptive requirements resulted in a building which was under designed.
The scary part….if you build to prescriptive requirements, and have a collapse, the Building Department is absolved from any structural liability!
THE SOLUTION – IF a Building Department has PRESCRIPTIVE REQUIREMENTS for Pole Buildings – invest in an engineered building kit. It is less expensive to pay for the engineering and it guarantees a building which will be designed to actually meet the building codes. Your bonus is the sealed plans are your “insurance’ – the engineer is now liable to for the safety and integrity of your new building.