The rate of new housing production plummeted during the 2008 financial crash, and has not yet fully recovered, exacerbating a nationwide housing shortage. The U.S. Census Bureau found that, in 2005, approximately 2.2 million units of housing were authorized for construction, which is more new units than between 2008-10 combined. The drastic fall in residential construction resulted in the lowest recorded number of new housing permits in the last 60 years: the U.S. authorized the construction of fewer new homes between 2010-2019 than any of the previous 5 decades. In New York City, “permits for middle density buildings were reduced by almost 70% in the post-recession period,” writes Marcel Negret, in a report for the Regional Plan Association. The deficit, he says, “represents almost the entire decline in housing production overall between the pre and post-recession periods.” The global pandemic in 2020 caused further problems by disrupting supply chains and elevating the costs for materials and labor.
Housing emerged as a headlines issue in recent years, but the problem has been decades in the making. Although middle housing types – such as duplexes, fourplexes, and townhomes – were commonly developed prior to the 1940s, limited new construction has effectively split the market into single-family homes and multifamily apartments. Zoning and land use regulations have become increasingly rigid and widespread, resulting in both the explicit and implicit exclusion of mid-sized housing options. An explicit exclusion is a restriction upon the types of housing that can be permitted by-right within a particular zone. “By-right” or “as-of-right” refers to development that is allowable without undergoing a land use review process. Development projects that are not “by-right” are subject to public hearings where proposals can be rejected, postponed, or required to complete costly studies.
The significance of single-family zoning is not that it allows for single-family homes, but that other more naturally affordable housing types are excluded. The amount of residential area zoned exclusively for by-right single-family housing in Connecticut is 70.2%, according to Sara Bronin, founder of the National Zoning Atlas. Similarly, analysis by Housing Works RI found that 87% of the state is zoned for single-family housing by-right, while by-right zoning for multi-unit options is much lower: 20% for two-family, 9% for three-family, and 8% for four-family. New policies are being introduced to expand the types of housing that can be built, in addition to single-family, by loosening zoning and land use regulations.
In 2024, Connecticut passed H.B. 5474, which offers incentives to municipalities that adopt zoning regulations allowing “middle housing” to be developed by-right on any lot that allows for residential, commercial, or mixed-use development. Similarly, in 2021, the state passed H.B. 6107 to allow the by-right development of accessory dwelling units (ADUs) in designated zones and on lots permitting single-family homes, although municipalities can opt-out with a large enough majority. In Rhode Island, a package of 14 housing bills passed in 2024, including H.B 7062, providing statewide rights to develop ADUs, and H.B. 7980, which allows manufactured housing development by-right wherever single-family housing is allowed.
In 2019, Oregon passed H.B. 2001, becoming the first state to eliminate exclusive single-family zoning, thus allowing a range of middle housing types anywhere that single-family homes are also permissible. Only a handful of states have passed similar legislation, including California, Washington, and two northeastern states. Maine passed L.D. 2003 in 2022, and Vermont passed S.100, or the HOME Act, in 2023, both of which expand the variety of housing options wherever single-family homes are allowed. “If that kind of legislation is introduced, you’re allowed to build middle housing in a single-family neighborhood, which means that single-family will exist along with the middle housing development,” said Samar Jha, government affairs director for AARP, who spoke at CSG East’s 63rd Annual Meeting.
Zoning regulations can also result in the implicit exclusion of various housing options by imposing mandates, which may increase development costs to the extent that middle housing types are no longer financially feasible to develop. For example, parking requirements, minimum lot sizes, building height restrictions, or other mandates, can affect the cost of housing. Maine and Vermont each found ways to reduce some restrictive mandates. To reduce the costs of an affordable housing development, Maine’s L.D. 2003 limits the parking requirements to 2 spaces per 3 units, and for ADUs, the law prevents the conditional requirement of any new parking spaces. Vermont’s HOME Act limits parking requirements to 1 space per unit in areas served by sewer and water. New Hampshire has also taken strides to curtail exclusionary zoning. In 2016, the state legalized ADUs statewide with the passage of S.B. 146, and in 2024, it passed H.B. 1400, which reduces residential parking requirements to 2 spaces per unit. In 2021, New York proposed S. 7574, aiming to reduce minimum lot sizes, prohibit off-street parking as a requirement, and legalize middle housing on any residential lot with additional density permitted near transit; however, the bill did not pass.
Other states have found incremental ways to cut the red tape around the development of ADUs, middle housing types, and manufactured housing, to expand the availability of housing options in single-family zones. Maryland passed the governor’s three-bill package of housing legislation in 2024, including H.B. 538, or the Housing Expansion and Affordability Act of 2024. “On all single-family zoned property in the state, now, in every county and every jurisdiction, modular and manufactured housing is allowed by-right,” said Jake Day, the secretary of Maryland’s Department of Housing and Community Development, at CSG East’s 63rd Annual Meeting.
Massachusetts also legalized ADUs in 2024 with the passage of a historic $5.16 billion Affordable Homes Act, or H. 4977. In a panel discussion at CSG East’s 63rd Annual Meeting, Secretary Ed Augustus, who leads the Massachusetts Executive Office of Housing and Livable Communities, described some of their initiatives and outlined the realistic challenges still imposed by the housing crisis. He said, “All of the things that challenge us to build housing: high interest rates, high construction material costs, the availability of land and parcels that you could assemble to create developable zones are still there. We’re just saying we’re removing one factor from the barriers to housing production, which is zoning.”
States are continuing to explore zoning reforms that would accelerate the production of new housing and allow for a wider variety of housing options to be available at lower costs. For more on upcoming policy events and how to access CSG East housing policy resources, contact housing policy analyst Joseph Shiovitz at jshiovitz@csg.org.
