Off-site construction can decrease project time by 50% (Page 3) due to industrialization of the building components and the ability to complete site work, such as laying the foundation, concurrently. These time-saving benefits are lost, however, when there is uncertainty about who or how these structures and processes are inspected and deployed. Since the process of how these structures get commissioned varies from state to state and even city to city, each new project may encounter its own set of hurdles.  

The 1200 Series Standards

The uncertainty caused by this state and/or municipal patchwork of regulations led the International Code Council and Modular Building Institute (ICC/MBI) to introduce the 1200 Series Standards for Off-site Construction in 2021. These standards can be adopted by individual jurisdictions and even be adopted statewide. The standards are as follows:

• ICC/MBI 1200 (2021): addresses planning, design, fabrication and assembly of off-site construction.  
• ICC/MBI 1205 (2021): addresses the inspection, approval, regulatory compliance of off-site residential and commercial components and their assembly and completion at the final building site.
• ICC/MBI 1210 (2023): addresses mechanical, electrical, and plumbing system elements with respect to energy efficiency, water conservation, planning, designing, fabricating, transporting and assembly within commercial and residential buildings. 

Off-site Construction in the Midwest

No jurisdiction in the Midwest has adopted the ICC/MBI Standards. However, this does not mean off-site construction isn’t happening in the region. In fact, in 2022, 6% (7,000 homes) of the region’s 137,000 housing units were completed using non-site build construction methods, the second highest percentage based by region in the country. Like other regions, the Midwest is experiencing a shortage of affordable, efficient housing. Creating a system that allows off-site construction to flourish would be another tool in the toolbox to alleviate the housing stresses currently affecting millions, while simultaneously paving the way for a construction process that produces less waste, provides better working conditions and creates higher quality energy efficient homes.

This provides a great opportunity for jurisdictions in the Midwest to capitalize on this area of development already happening in the region. A city or state that implemented these standards would signal to builders and factories that they are off-site construction friendly and well equipped to handle the process, creating jobs and providing homes quicker for their region.

In 2021 Salt Lake City, Utah, was the first jurisdiction in the country to implement the ICC/MBI 1200 and 1205, paving the way for off-site construction to help alleviate their affordable housing issues. Shortly after Salt Lake City adopted these standards, the Commonwealth of Virginia adopted the standards at a statewide level and most recently, in 2024, Utah took them statewide as well.

Off-site Construction and Code Implementation

There is nuance to off-site construction that is important to understand. It can be sometimes conflated with manufactured housing. While manufactured housing is a type of off-site construction, the building codes that apply to manufactured houses are based on the U.S. Department of Housing and Urban Development (HUD) Code. The HUD Code, unlike conventional building codes, requires manufactured homes to be constructed on a permanent chassis. Off-site construction, or modular homes, are constructed to the same state, local or regional building codes as traditional site-built homes.  

Implementation of the 1200 Series Standards is particularly effective in states that do not currently have a state-wide off-site construction review process, and instead leaves off-site construction review to the local jurisdictions. In the Midwest this is the case for South Dakota and Kansas, though adoption of these standards in any state would facilitate the off-site construction process greatly.  

Getting standards adopted varies from state to state.  If you would like further information about how your jurisdiction can get the 1200 Series Standards implemented, please contact Alison Lindburg, Director of Building Codes & Policy.