s060705 Four Dwelling Limitation Clause

Identifier: s060705

Date: 08/21/2006

Question

What is the significance of the 4 or fewer dwelling units….Is it an arbitrary number, or are there code implications?

Response  

The four dwelling unit limit in the ASHI Standards of Practice (SOP) began in the late 1970's when the standards were first developed.  One reason for the limit, at that time, was a federal definition of a residential property as one with up to four units. 
The four dwelling unit limit continues to apply, based in part on provisions of the International Residential Code (IRC).  The scope provision says that the IRC applies to one and two-family residences and to townhomes.  The definition of a  townhome, as a practical matter, limits it to four dwelling units in one building.  Other residential occupancies would fall under the International Building Code and could include components, systems, and construction techniques not normally found in dwellings built under the IRC.