Electrical infrastructure in low-rise multifamily and manufactured homes in the United States: a national online survey

Abstract

Residential electrical infrastructure upgrades play a central role in supporting home improvements and modernization, yet such upgrades are often costly and time-consuming. Understanding the current state of residential electrical systems is essential for evaluating upgrade needs. Existing data sources largely focus on single-family homes, while far less is known about multifamily and manufactured housing, despite their significant share of the U.S. housing stock.To address this gap, we conducted two nationwide online surveys, each tailored to one housing type. For multifamily dwellings, data were collected at the apartment level, including vintage, floor area, location, and fuel type for major equipment such as heating, cooking, water heating, and dryers. Respondents also submitted photographs of apartment subpanels and service disconnects. For manufactured homes, the survey included these same details along with additional questions on home type (single- or double-wide) and the type of electrical service connection to the home, distinguishing between overhead and underground supply. After data review and validation, the final analytic sample included 156 multifamily dwelling units and 108 manufactured homes.We found clear differences between the infrastructures in multifamily and manufactured buildings. Multifamily dwelling units most commonly had smaller service disconnects of <100A (22%), 100A (50%) and 125A (19%). Few had 200A service (6%), indicating substantially lower electrical capacity than in single-family homes. Manufactured homes, in contrast, were dominated by 200A services (69%), with most of the remainder at 100A (27%), a distribution broadly similar to single-family detached homes. Notably, 100A ratings were much more common in manufactured homes with 0-3 major electric appliances than were previously reported for single-family homes. 200A ratings dominated in both manufactured and single-family homes with 4 or more electric appliances. Both housing types and all service capacities had few unused breaker spaces (median values of two to five) for accommodating new electrical loads, representing an important physical limitation to housing improvements.The results establish a foundation for understanding infrastructure conditions in underrepresented housing types, with implications for affordability and resilience in the nation’s housing stock.

Keywords: Electrical panels, Housing survey, Multifamily housing, Manufactured homes, Electrical infrastructure