Accessory Dwelling Units (ADUs) are having a moment. Once commonly referred to as “in-law suites,” ADUs are becoming an important housing option increasingly supported by communities nationwide. These small, secondary homes share a property with a main residence, providing flexibility, affordability, and new opportunities for homeowners and cities alike.
Why ADUs Are Growing in Popularity
Historically, ADUs were restricted or outright prohibited by most zoning ordinances. Minimum lot size, parking requirements, and other barriers made them difficult—if not impossible—to build. In recent years, however, many municipalities have updated zoning codes to allow ADUs in single-family neighborhoods and have streamlined the permitting process.
This shift comes at a time of critical housing shortages. By increasing density without significant new development, ADUs offer a cost-effective way to expand the housing stock. For homeowners, they can also serve as a source of supplemental income, helping offset mortgage payments or other expenses.
Beyond economics, ADUs offer real flexibility for modern living. They’re an attractive option for multigenerational households, giving families space to live near one another while maintaining privacy and independence. Aging parents, adult children, or caregivers can all benefit from this arrangement.
More Than Just Housing
While ADUs are most often built as living quarters, they can serve a variety of functions. Homeowners are reimagining these spaces as:
- Home offices or studios
- Recreation or entertainment rooms
- Guest accommodations
- Personal fitness or wellness spaces
This flexibility makes ADUs a attractive long-term investment, capable of changing as family needs shift.
Our Work with ADUs
Our firm has been actively engaged in designing and constructing ADUs throughout New England, with several projects recently finished and many more in progress.
One of our current projects is especially noteworthy: construction has started on Brookline, Massachusetts’ first approved detached ADU under the town’s updated zoning ordinance. The project converts a two-car garage into a 700-square-foot, two-bedroom unit. Located behind a classic 1920s home, this ADU required careful management of building codes and zoning requirements, especially ensuring safe egress paths in case of fire—an especially important concern in densely populated neighborhoods like Brookline.
Another ongoing project in western New Hampshire takes a different approach. Here, we designed a modern barn with additional garage bays and a studio space above. Outfitted with a small kitchen and full bathroom, the studio offers flexible use as guest quarters or as a fully self-contained living unit when needed.
Our ADU project in New Hampshire’s Monadnock Region will share its site with an off-grid primary home that was state-of-the-art when it was built by the current owners 25 years ago. The owners plan to downsize and move into the 800 SF high-performance, off-grid ADU, while one of their adult children and their family will move into the primary residence.
Design Considerations for ADUs
No matter the location, a thoughtfully designed ADU should complement the character of the primary dwelling and the property as a whole. Municipal zoning ordinances typically limit ADU size—often capped at around 1,000 square feet — with height restrictions as well, so thoughtful, efficient design is essential.
Our goal with each project is to balance these practical constraints with the homeowners’ needs and lifestyle, ensuring that the ADU feels like a natural extension of the property rather than an afterthought.
Looking Ahead
As zoning ordinances continue to develop, ADUs are set to play an increasingly vital role in fulfilling housing demands and supporting new ways of living. Whether serving as homes for family members, income-producing rentals, or flexible bonus spaces, ADUs reflect the growing need for adaptable and sustainable housing solutions.