Accurate Review


Existing Building Code

An Accurate Review White Paper, Spring 2018


By:  Kevin Walsh, AIA



The International Existing Building Code:



With more and more buildings being repurposed, the International Existing Building Code (IEBC) published by the International Code Council (ICC) is more relevant today than any time since it was first published in 2003. Because building Codes are revised on a three year cycle and most Villages adopt them in a 6 year cycle there exists a large inventory of existing buildings built under previous editions of the International Building Code (IBC) and therefore are not 100% in conformance with a newer adopted versions. This White Paper is intended to give design professionals some insight on how to design using the IEBC in lieu of trying to bring the entire building up to the newest adopted building Code.




Existing Buildings had been addressed in chapter 34 of the IBC until the 2015 edition. Since 2003 the ICC has had a separate document (IEBC), this document was not widely adopted, meaning Chapter 34 of the International Building Code was used. Following the 2012 addition of the International Building Code (IBC) Chapter 34 has been deleted. With this deletion, existing buildings are now addressed in section 101.4.7 of the IBC which states “The provisions of the International Existing Building Code shall apply to matters governing the repair, alteration, change of occupancy, addition to and relocation of existing buildings.”


The main reason behind having an International Existing Building Code is to allow a Design Professional to use an alternate method of coming into compliance when bringing the entire existing building into compliance with current building codes is cost prohibitive. The main idea behind the International Existing Building Code is that any additions or alterations would have to comply with the new codes, but the existing buildings need only to be maintained to their current level of safety. It gives the Design Professional three different methods it comply with the code when dealing with an existing structure.




The IEBC allows design professionals to use one of three methods to comply. The fourth method not listed in the IEBC would be to follow the IBC in its entirety. Again if following the latest IBC is cost prohibitive, it is up the Design Professional to select and design to one of the (3) methods in the IEBC. The three methods are the Prescriptive Compliance Method, the Work Area Method and the Performance Method.

The Prescriptive Compliance Method was born from the old Chapter 34 of the IBC (previous to 2015). This method is laid out in less than 10 pages of Chapter 4 of the IEBC; that by itself will give you an idea of how little it deviates from following the entire IBC. In the first paragraph of section 403, the code reads “Except as provided by section 401.2 or this section, alterations to any building or structure shall comply with the requirements of the IBC for new construction”.  Although this method is the easiest for a Design Professional to follow it, is in general the most restrictive.

The Second Method, the Work Area Method treats repairs, change of occupancy, additions, historic buildings and relocated buildings separately from alterations. Alterations are further defined as Level 1, 2 or 3 depending on the amount of work. Although this method is harder to determine what applies and what does not, it allows much more flexibility to the Design Professional. Our approach to this method has always included a meeting with the Local building Official to review the planned Design before embarking on the complete Design.


The Final Method is the Performance Compliance Method. There are two basis ideas with this section: 1.) Alterations while not required to meet the requirements of new construction (IBC) will improve the current existing situation.  2.) The provisions are based on a scoring system that includes 19 various safety parameters, and the degree of code compliance of each.




We are often asked if the building is having a new owner or new tenant how the International Building Codes in general applies. The IEBC is pretty clear that is there is a Change of Occupancy the new occupant must apply for a building permit and is the occupancy changes in use group or division of the use use group it is required to comply with the entire requirements for the new occupancy for the entire building. There is a provision that allows this to be waived by the building official only when the new occupancy is of a less hazard than the previous one.




It is typically easiest, but not the most cost effective to just follow the entire IBC when re-purposing, renovating or adding on to an existing building. However, the above three compliance methods offered in the International Existing Building Code offer some alternatives that are more reasonable.








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