With the introduction of the 2024 Ohio building Codes, it was apparent that something different was being done with existing buildings from past Ohio Codes. After all there was a whole new book sitting on a shelf, where previously there was only a chapter. So it was no surprise that after putting together my Top 5 Most Impactful Changes You Need to Know About the 2024 Ohio Building Code I began getting inquiries into what changes might impact Ohio’s existing buildings. So with that in mind:

1. New Home for Chapter 34

What was previously found in chapter 34 of the Ohio Building Code has found a new home in the Ohio Existing Building Code. The OEBC even though going through significant “Ohioization” is not a completely new code but is based on the 2021 International Existing Building Code with significant input from chapter 34  of the 2017 Ohio Building Code. The primary takeaway is that for the first time, there is a model code reference commentary for many of the sections of code found within the Ohio Existing Building Code by looking at the 2021 IEBC Commentary. 

2. Three Compliance Paths

The OEBC introduces three compliance paths for existing buildings: 

• The Prescriptive Compliance Path (301.3.1 – Chapter 5) – which borrows heavily from the old Chapter 34
• The Work Area Compliance Path – (301.3.2 and chapter 6-12) – all new to Ohio 
• The Performance Compliance Path (301.3.3 and Chapter 13) – which follows much of the previous Chapter 3412 of the Ohio Building Code. 

Architects and engineers must state to the authority having jurisdiction which path their project will follow when modifying existing buildings. 

3. Additions to Existing Buildings

One of the more unique code sections found in the former OBC’s chapter 34 has to do with additions to existing buildings. The OEBC chapter 502.1.1 expands on the previous code that created a pathway for adding on to existing buildings without a firewall where the addition and the existing structure exceeded the allowable area. This alternative compliance path now clarifies: 

• What can be done when the addition and the existing building would be required to have sprinklers per chapter 9 for fire area. 
• The intent of what is required for additions with sprinklers when the existing structure does not have them. 

4. Changes of Occupancy

One significant difference in the IEBC that is not in the OEBC can be found in the prescriptive compliance method (506) regarding a change of occupancy. The IEBC states that an existing structure undergoing a change of occupancy does not need to comply with all the requirements of the code for the new code provided the new occupancy is less hazardous. In IEBC chapter 1011 under the work area method there are tables which outline in more specificity the relationship of the uses as it pertains to hazard. While these same tables can be found in the OEBC, the OEBC version of chapter 506 requires a point analysis per chapter 13 to determine if the new use is less hazardous.  As a designer I prefer the IEBC methodology as it is simpler, but I can respect the use of the point system found in chapter 13 to determine hazard. 

5. Performance Compliance Method

To get an existing building to meet the requirements of the performance compliance method has never been easy.  Not only are the calculations involved complicated, but the modifications necessary to an existing building to obtain the required points may leave the architect and owner wondering if it would just be simpler and cheaper to modify the existing building to comply with the requirements of the building code for new construction . The 2024 OEBC uses the same required points found in the IEBC which are 2-6 points higher than what was found in the 2017 OBC. Meaning it just got more expensive as more remediation will be needed to make an existing building compliant using the performance method. 

Honorable Mentions:

• Even though rarely enforced, the previous building code limited the use of the performance compliance method to buildings built prior to 1979. That somewhat arbitrary limitation is no longer found in the 2024 OBC.
• Several errors in the performance compliance method were corrected in the 2024 OEBC for I2 uses. 
• When altering spaces adjacent to existing sleeping rooms in group R or I-1,  smoke alarms shall be provided. 
• Installation of carbon monoxide detectors is required in existing buildings for use groups I-1, I-2, I-4 and R.
• Alterations to existing 911 call stations, EMS and police stations shall include a storm shelter.