Overview
§15A-1-302 of the Utah State Code defines factory-built housing as a manufactured home or mobile home. Modular housing, known in Utah as a “modular unit” or “modular building” unit is defined separately from a factory built housing and is defined as a structure constructed from one (1) or more modules or panelized systems that is manufactured in accordance with the State Construction Code and transported to a location, the purposes of which is for human habitation, occupancy, or use.
It is important to note from the outset that these two terms are not interchangeable under Utah law. Factory-built housing (i.e., manufactured homes (formerly known as mobile homes) is regulated primarily under the HUD Code, while modular units are governed by the State Construction Code. The lessons that follow will walk through each category in detail, including how they differ from one another and from other housing types that are frequently confused with them.
Some of the many benefits and advantages to utilizing factory built and/or modular housing include:
- Lower Production Costs. Factory built and/or modular housing are more cost effective than traditional site built construction due to streamlined production processes including bulk material purchases, reduction of construction waste, and by maximizing labor efficiency.
- Increased Quality Control. Factory built and/or modular housing adhere to strict quality standards during production, including undergoing rigorous inspections. Improved construction methods and materials also enhance the unit’s resistance to weather and natural disasters, making the unit more durable over time.
- Predictable Timelines. Unlike typical site built construction, which can be delayed by various weather conditions, factory built and/or modular housing can adhere to more predictable production timelines due to controlled conditions inside factories which minimize human errors and material defects, resulting in a higher-quality end product for the consumer.
Navigating the different facets of factory built and modular housing can be daunting. Especially when construction terminology starts to intertwine with land use terminology and the various requirements set forth by the State.
Content Contributors: Jones and DeMille Engineering, Inc, Hansen Planning Group, LLC / Rural Community Consultants
Special Note: This material was developed by civiclinQ for the Land Use Academy of Utah (LUAU). Funding for the development of this material was provided by through the Land Use Training Fund, which is administered by the Office of the Property Rights Ombudsman , utilizing a portion of the 1% surcharge on all building permits in the State of Utah.
The role of this organization in administering funding is primarily administrative and should not be viewed as legal advice. Always consult your legal representative when addressing land use activities.
Use the ‘Materials’ tab above to view related course materials, including printable pass-along card and PDF version of this online course.

