This is where L&I's rules come in which brings me to the conversation I had with the very first, and the second director of L&I's UCC division starting in the very beginning in 2004 and continuing to my last discussion with the second man in charge in 2016.
First and foremost, a commercial building must have a CO or a record of a CO. If it does not at the local level and L&I has no records; then it is considered an uncertified building, and no matter what it was used as it is a change of use and occupancy. I've been through this dozens of times with L&I along with all of the businesses in multiple jurisdictions.
For example a lady purchased a hair salon to open up a hair salon. Her state license required that she have a CO. She called me for a CO and I said we only issue COs to permitted work, as the permit number is the first thing required on a CO. I told her to contact L&I and have them search their records for a CO form the old 1928/29 PA Fire & Panic Act. L&I was unable to find one, therefore a CO did not exist and it was considered an uncertified building.
She could not operate without a CO and the only way to get one was to pull a permit to do work and since there were no records, was a change of use and occupancy renovation. She had to comply with the IEBC and make the necessary changes in order to get a CO and operate legally within her license requirements.
Like I said, we did this dozens of time with the guidance of L&I for years without any problems. That is the way it is in PA.