I have recently received several questions about townhouses and realized that there are several misconceptions people have of them. The purpose of this article is to address some of those misconceptions. Townhouses are governed by the International Residential Code (IRC) and thus must comply with the requirements found in the IRC. First, the building must contain three townhouse units before it is considered a townhouse. This is established by the definition of townhouse found Chapter 2 of the IRC. If the building only contains two dwelling units, it is a two-family dwelling. Second, the building, containing three or more units, must meet the following four items:
- The building shall not be greater than three stories above grade plane, and
- Each unit shall be open on no less than two sides, meaning a yard or public way is present, and
- Each unit shall have it’s own means of egress, and
- Each unit shall extend from the foundation to the roof. This means units cannot be stacked upon one another and be considered townhouse units.
There is no limit in the IRC on the number of townhouse units that can be constructed in one building. With that stated, a specific jurisdiction’s zoning regulations may limit the number of units, or the jurisdiction may have amended the IRC during the adoption process to limit the number of townhouse units in a single building. The ability to build an endless amount of townhouse units in one building is the driving force behind the fire separation requirements of such units as stated in Section 302.2 of the IRC.
If the building you are working on contains more than two units and does not comply with the requirements mentioned for a townhouse then it must comply with the requirements of the International Building Code.
Hopefully, you find this information useful, and it provides some clarity on the matter for you.
References: This article was based on the 2021 edition of the International Residential Code as printed by the International Code Council. Specifically, Section 101.2 and the definitions of townhouse and townhouse unit found in Chapter 2.
