Accessory dwelling units (ADUs) are a flexible feature that can meet an array of needs and trends for homes and homeowners today: affordability, wellness, multigenerational living, and remote work.
ADUs have spiked in popularity recently, according to data from the American Institute of Architects, and it's been bolstered by the introduction of more ADU-friendly zoning laws in California and Americans’ shifting perspectives and changing needs on and from their housing.
These smaller residential units are located on the same lot as a single-family home and are known by many names, such as granny flats and in-law suites, for example. They can be both newly built detached structures or remodeled and converted parts of an existing home.
“Since households are doing more at home, they have been looking for more space during the pandemic,” said AIA Chief Economist Kermit Baker in a statement accompanying AIA’s 2021 second quarter Home Design Trends Survey. “This has included focusing more activities outdoors and adding other buildings to their property.”
The study found a 20% increase from 2020 to 2021 in firms reporting requests for accessory dwelling or rental units, bringing the total to 74% of surveyed firms. The study also noted increases in requests for finished basements, attics, and micro-housing options.
Developments of ADUs go as far back as the early 20th century, according to the Department of Housing and Urban Development. When the need for housing skyrocketed after World War II, the suburbs boomed. As suburbs grew, jurisdictions outlawed ADUs to keep housing density low. Restrictions then popularized illegal ADU construction in areas with low housing stock, such as San Francisco.
Photo: courtesy United Dwelling
The same trend that spurred ADU construction continues now. ADUs can be a viable solution for adding more affordable housing stock into the market while providing a revenue stream for homeowners. They can also be a way to keep aging loved ones close while retaining privacy, a home office, gym, and guest house.
Steven Dietz, CEO of Los Angeles-based United Dwelling, an all-in-one ADU design and build company aiming to make the process streamlined, simple, and low-cost, says half of their homeowner customers are older adults bordering retirement age and looking for a way to stay in their homes. Dietz says ADUs are a way for homeowners to monetize their assets and increase their value without selling.
Though small, these spaces have a big role to play, whether it be an income-generating rental, a solution for more living space, or a place for visitors. Designing a new ADU or remodeling an existing structure requires several key considerations as the spaces average out around 900 square feet, according to Italian appliance manufacturer Bertazzoni’s 2021 Kitchen Trend Report, though accepted ADU sizes depend on municipalities.
Residential design and build firm Duoma Atelier says the most common request they receive for ADU projects are guest houses, home gyms, and in general, flexible spaces that can change to meet shifting needs.
“Clients may not need [these spaces] two, three, or four years from now, and they may want to do something else with the space, but it’s still a useful space without having to tear it down or do a major renovation to change things inside,” says Duomo Atelier co-founder Gaston Galella. “We always keep that in mind: being flexible enough to reconfigure and utilize the space for other purposes.”
If the ADU is a long-term or short-term rental, the products and features inside need to be durable and simple, says Dietz.
“The very first consideration is that the materials that are used are robust enough to stand up to rental use,” explains Dietz. “The second thing we focus on, again partially because they’re rental units, are simplicity of use. Appliances that have a limited number of choices, high-end appliances that have 27 settings for how you wash your clothes just aren’t appropriate for the environments we’re in. The next is energy efficiency because the way the rules are written, by far the most economic way to build an ADU is to have it tied to the meter on the main house.”
Practicality is another key consideration Dietz notes for specifying an ADU’s products and features. Just one person typically resides in a United Dwelling studio or one-bed unit, which means smaller appliances make sense. The company opts for a smaller convection microwave oven, cooktop, and smaller fridge.
But that doesn’t mean smaller is always better. Areas and products a tenant uses daily should be both useful and comfortable.
Photo: courtesy United Dwelling
“After the first few units built, we actually realized we wanted to make the bathroom larger so the showers a good size, so the toilets a standard size,” says Dietz. “And we had to take that space from somewhere, so we took it out of the living area. But those extra three square feet in the bathroom make a huge difference.”
And to drive value for a rental listing, high-impact kitchens with quality, size-appropriate appliances that look beautiful are key, says Bertazzoni.
And well-known design tricks that make compact areas feel large are just as important, such as using light colors and raising ceilings. Large glass bi-fold doors can help make any small square footage feel spacious, and it ties interiors to the exteriors, adding a wellness aspect.
“There's a lot of considerations when it comes to wellness,” says Duoma Atelier co-founder Norma Galella. “The biggest thing that we consider, if we're doing an expansion or a flex room, is natural lighting. But there's so many components […] Having a water station near your home office, something that would promote hydration. Having a snack bar with healthy snacks, even having things that promote joy.”
Offered in sizes between 15 and 25 inches, the Siena workstation sink by Ruvati meets the need of different kitchen sizes. It helps to retain countertop space and even acts as an extension of the counter when the solid hardwood cutting board accessory is fitted on top. It also comes with a stainless steel colander accessory and can be installed as a topmount or undermount sink. It features 10 inches of depth and a 16 gauge stainless steel profile that promises to never rust or stain.
Bertazzoni says its high-quality form and function are not sacrificed in its smaller, compact appliances. The 24-inch All Gas Range features a dual ring 19,000 BTU burner that claims to boil water in just six minutes and three additional burners with 750 BTUs. The interior offers 2.4 cubic feet.
Italian modular kitchen brand Very Simple Kitchen focuses on two main ideas: functionality and style. The brand’s 100% stainless steel kitchen systems can be configured in any way imaginable and provide maximum flexibility by being freestanding systems. If the needs of an ADU changes, the kitchen can be moved. The company includes ranges, cooktops, and dishwasher appliances in their configurations as well. Very Simple Kitchen welcomes custom colors or residential pros can select from their standard color offerings.
Bosch’s 800 Series washer and dryer measure 24 inches wide and about 70 inches tall when stacked. Both are Energy Star-certified appliances that offer an energy-efficient and quiet motor, which can be ideal when living or working in a small space. The washer and dryer can finish a small load in just 15 minutes. The dryer’s moisture sensor prevents wasting energy and overdrying.
Though this product won’t roll out until early 2022, Thermador’s combo drawer refrigerator and freezer will be ideal for ADU housing guests, used as an office, or an extra lounge area. Its freezer and fridge capabilities allow for the storage of a wide variety of food and drinks in a smaller, more reasonable size.
This appliance saves time and money by combining a sink and dishwasher into one. It does take up countertop space, but it maximizes storage space by keeping the base cabinets. FOTILE says the dishwasher uses nearly half the amount of water as a traditional dishwasher but with the same sanitization and cleaning functionality. This solution could be ideal for ADUs with older adults, as it eliminates the need to bend down when loading and unloading dishes.
Bathrooms with little square footage mean it’s likely there’s insufficient clearance for a swinging or pivoting shower door. Showers will also likely be the largest element in a small bathroom, meaning its design should feel large when inside but appear to take up minimal space from the outside. Coastal Shower Door’s Eclipse door slides open on smooth gliding rollers with overlapping glass panels that allow for an illusion of a larger shower.
A well-known trick to enlarging small spaces is using large mirrors. Wetstyle’s 30-inch tall recessed medicine cabinet offers the large mirror part while also acting as a necessary storage spot. It features slow-closing doors, an all-natural wood veneer, and an extra deep interior.
Extra-large folding and sliding glass doors are a popular way for homeowners to expand their interiors and connect their homes to the outdoors. Adding this feature to an ADU can do the same, while also maximizing the square footage and natural light. NanaWall’s SL60 option works well in all climate types while maintaining high energy efficiency through a built-in insulation barrier.
This wall-mount vanity helps maintain precious floor space in smaller bathrooms while offering a full-sized counter, sink, and storage. It measures 25.75 inches wide and the corresponding sink measures 34 inches wide. The tapered nature of the vanity helps the fixture take up less space. Libera is ADA-compliant and comes in several different variations, including a double vanity and a larger 31-inch wide model.
Convenience and wellness needs for all spaces, even ADUs, are important considerations. Having readily available drinking water and hot water for teas or coffees are important needs for any guest in any type of ADU, whether it be for a gym, guest house, or home office. Waterstone’s hot and cold faucet works with the brand’s Ultimate Filtration System, features textured knurling accents, and comes in 32 different finishes.