Accessory Dwelling Units (ADUs): Maximizing Space and Comfort

Accessory Dwelling Units, or ADUs, have become popular as local municipalities have relaxed regulations to allow more homeowners the opportunity to create independent residential spaces. In this article we explain what makes ADUs unique, and some of the special considerations when deciding to build one such as whether to retrofit within an existing home, or whether to build an addition or detached living space.

An accessory dwelling unit (ADU) is a self-contained residential unit located within or on the same lot as an existing single-family home. An ADU has all the basic facilities needed for day-to-day living independent of the main home, such as a kitchen, sleeping area, and a bathroom. In most cases, the homeowner must occupy either the ADU or the primary home. One of the primary goals of ADUs is to help create more habitable units in one-family housing zones.

In Massachusetts, not all cities and towns allow for ADUs, and regulations, such as size restrictions and types of building permits, are set by the municipality. For instance, in Newton, ADUs within an existing home (space conversion) only need a regular building permit, whereas an addition or detached building requires a special permit. There are differing size restrictions depending on whether it is a space conversion or detached ADU. No short-term rentals are permitted. You can find out exactly what is and what isn’t allowed by town here.

Before: Extra bedroom above the garage to be converted into an ADU.

One of the ADUs we completed in Newton includes examples of some of the considerations and design decisions we made to comfortably accommodate aging parents in what once was a spare room above the garage. We designed and built a 365-foot ADU with abundant light, as well as features to accommodate aging in place. For energy efficiency, we installed a ducted heat pump system and an ERV (energy recovery ventilator) to help control humidity levels, clean indoor air, and save on utilities.

The ADU regulations required two separate means of egress. To create a separate main entrance, we took one bay of the garage to build an entryway and staircase to the second-floor ADU. We also built a small office/guest room in this bay for use by the homeowners. The curving staircase includes a stair chair lift for accessibility; room to accommodate the stairwell was carved out under the platform bed. 

As you walk up the stairs a half wall separates the stairs and living area, allowing for more light and making the 365-foot space feel larger than it actually is. The in-laws have been able to keep their favorite belongings close at hand and added a futon in the living space for more sleeping area.

The real challenge was how to get all the appliances into the kitchen. Our solution was small versions of everything! This petite kitchen is fully outfitted with a 24” GE electric range, XO exhaust hood which vents to the outside, Haifle 18” dishwasher, Blomberg 23” bottom freezer fridge, and even a Haier 24” washer/dryer combo. The drop leaf table provides seating for 2 or expands when the grandkids pop upstairs for a visit. Again, use of windows is critical in making the space airy and bright.

Accessibility and aging in place were designed and built into the bathroom, as well as the staircase. A large curbless shower with grab bars also boasts controls close to the opening to make it easier to turn on the water and get it to just the right temperature before stepping in.

Needless to say, designing and building an ADU is not a quick or easy process; it requires expertise to adhere to building codes while making a very tiny space have all the conveniences and comforts of larger homes. As on all our projects, we work with the homeowners to consider Universal Design to accommodate people of all abilities and consider aging in place options. And, it wouldn’t be a steveworks design if we didn’t add energy-savings features.

Considering an ADU? Please contact us and let’s brainstorm!

A curved staircase to the ADU includes a chair stair lift for accessibility.
The stairs extend under the left half of the platform bed. The right half flips up for storage.
Three windows allow light into the living area. A half wall makes the space feel larger.
This small kitchen has the convenience of modern appliances in petite sizes. On the right is a door to an outside staircase, the second means of egress.
Shower is designed for people of all abilities.