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Municipal Technical Advisory Service (MTAS)

Original Author: Broughton, Jeff
Date of Material: 07/27/2015

Zoning--Architectural control
Construction--Laws and regulations
Building permits

Regulating the Minimum Size of a Residential Dwelling

Reviewed Date: 04/28/2021
MTAS was asked whether it is lawful to regulate the minimum size of a residential dwelling through zoning or subdivision regulation.

April 28, 2021
Chuck Downham, Municipal Management Consultant

According to Section R304, Minimum Room Areas, of the 2018 International Residential Code (IRC), the minimum habitable area for a room is 70 square feet. Habitable rooms shall not be less than 7 feet measured in any horizontal direction. 

The minimum habitable area requirements have changed over the years for the various editions of the IRC. Cities have adopted various editions of the IRC so it is therefore recommended that a city review the specific edition of the IRC that has been adopted to confirm the minimum habitable area requirement that may be applicable and enforceable under the IRC if adopted by a city.

Main Document(s):
file Shannon Copas%2C letter%2C tiny homes with attachments.pdf