Massachusetts 2025-2026 Regular Session

Massachusetts House Bill H4163

Introduced
5/29/25  

Caption

Relative to accessory dwelling units inclusion in the subsidized housing inventory

Summary

H4163 creates a new state-level accessory dwelling unit local initiative (ADU-LI) within the Executive Office of Housing and Livable Communities to encourage municipalities to promote and preserve accessory dwelling units, or ADUs, as a source of affordable housing. The program is designed to support a range of living arrangements, including traditional rentals, family caregiving, home-sharing, and intergenerational occupancy, while tying participation to affordability and owner-occupancy requirements. Under the bill, municipalities that adopt an ADU-LI must submit their proposed agreement to the executive office for approval. Approved local initiative units would become eligible for inclusion in the municipality’s subsidized housing inventory if they are subject to a recorded affordability restriction, rented to households at or below 80% of area median income, and maintained under a model agreement for at least 10 years. The bill also directs the executive office to create regulations, a model agreement, a grant program, and a statewide resident matching service to help connect homeowners with compatible occupants.

Impact

The bill would amend Chapter 23B to add a new ADU-LI framework and Chapter 59 to create a special property tax assessment rule for land subject to an ADU-LI agreement. Properties participating in the program would be assessed based on the restricted use of the ADU, with valuation capped at 75% of fair cash value, and would revert to full market-value assessment if affordability restrictions are violated. The measure also authorizes municipalities to use affordable housing trust funds, community preservation funds, or other dedicated local housing resources to support ADU-LI development or preservation.

Sentiment

The bill appears generally supportive of affordable housing expansion and housing flexibility, with a policy emphasis on encouraging small-scale, owner-occupied housing options. Although there is no recorded committee testimony or vote history in the provided materials, the structure of the bill suggests a favorable orientation toward local participation, financial incentives, and administrative support for homeowners and municipalities. The absence of recorded opposition or amendments in the available context means no formal sentiment split is documented here.

Contention

The main potential points of contention are likely to be the affordability and compliance requirements imposed on participating homeowners, including the 10-year income restriction, annual income certification, owner-occupancy mandate, and the possibility of losing the tax benefit if restrictions are violated. Municipalities may also differ on whether to adopt the program, since participation is voluntary and requires local agreement approval by the executive office. Another possible issue is the use of public or dedicated local housing funds for ADU development, which could raise questions about fiscal priorities and administrative burden.

Companion Bills

No companion bills found.

Previously Filed As

MA H1484

Relative to accessory dwelling units

MA SB543

Accessory dwelling units and junior accessory dwelling units.

MA HB1136

relative to accessory dwelling units.

MA SB1117

An act to amend Section 66311.5 of the Government Code, relating to land use.

MA S1002

Relative to accessory dwelling units on smaller lots

MA H3469

Accessory Dwelling Unit Affordable Housing Incentive Act

MA H4020

Relative to owner occupancy requirement for accessory dwelling units

MA S1474

Allowing moveable tiny houses as permanent residential dwellings and accessory dwelling units

MA H1493

Allowing movable tiny houses as permanent residential dwellings and accessory dwelling units

MA H4707

Allowing movable tiny houses as permanent residential dwellings and accessory dwelling units

Similar Bills

CA AB1154

Junior accessory dwelling units.

CA SB9

Accessory Dwelling Units: ordinances.

NJ A3488

Concerns development of accessory dwelling units and related municipal land use regulations.

CA AB2127

Accessory dwelling units: private sewage disposal systems.

CA AB956

An act to amend Section 50515.

CA AB1055

Accessory dwelling units: proof of residential occupancy requirements.

CA SB543

Accessory dwelling units and junior accessory dwelling units.

AZ HB4028

accessory dwelling units; requirements