How do you ‘ADU’? Entrepreneur launches Maxable to demystify process for granny flats

Growing up in La Mesa, Caitlin Bigelow well understood the benefits the small garage apartment at her parents’ home represented for her family. The daughter of two journalists, she never forgot that the extra rental income helped her parents cover their mortgage and their family’s expenses, enabling them to remain in San Diego.

Bigelow left San Diego for college, completing a bachelor’s degree in entrepreneurship and Spanish at Juniata College in Huntingdon, Pa. Then she launched a career in digital marketing and e-commerce, developing expertise while working for several California companies.

When she was ready in early 2018 to pursue her dream of starting her own business, she wasn’t quite sure what direction to take. Her memories of her parents’ old garage granny flat quickly came to the fore.

Now, she has made it her mission to educate the public about the benefits of creating secondary apartments through her business Maxable.

Caitlin Bigelow and her mother, Lynn O’Shaughnessy, pose in the new kitchen of O'Shaughnessy's converted garage apartment.

An early and enthusiastic client of Caitlin Bigelow’s business Maxable was her mother, Lynn O’Shaughnessy (right), who wanted to restore a converted garage apartment in her La Mesa home that she was using as an office back into a colorfully decorated accessory dwelling unit for family visitors and rentals.

(Jarrod Valliere / The San Diego Union-Tribune)

“We’re trying to help people understand what the potential is. If you can turn these underutilized garages into something beneficial for your family, that’s good,” Bigelow said.

It’s even better, she added, if you can also transform that space into desperately needed housing.

Building granny flats is now all the rage since the California legislature passed landmark legislation (SB 1069) in 2017, reducing or removing many state and local regulations and fees impeding their construction. Several subsequent legislative changes fixed the new law’s flaws and clarified and streamlined the permitting and regulatory process.

The state’s goal was to ease the chronic affordable housing shortage by allowing homeowners to build a secondary apartment or granny flat — officially known as an “accessory dwelling unit” (ADU) — on their property. Housing advocates viewed such construction as a quicker path to adding new homes than the lengthy process required for large-scale developments. Homeowners have built over 20,000 new ADUs since its passage.

The light, bright, modern kitchen in O'Shaughnessy's colorful kitchen gets illumination from new pendant lights.

The light, bright, modern kitchen in O’Shaughnessy’s colorful kitchengets illumination from new pendant lights and a new skylight.

(Jarrod Valliere / The San Diego Union-Tribune)

O’Shaughnessy and her daughte used salvaged wood from the garage rafters for shelving in the granny flat.

O’Shaughnessy and her daughter, both avid recyclers of reusable material, used salvaged wood from the garage rafters for shelving in the granny flat.

(Jarrod Valliere / The San Diego Union-Tribune)

In researching potential business opportunities and ADU design, permitting and building practices, Bigelow observed that construction of new units was slow to take off despite the changes.

She realized that most people considering building a second unit on their property had no idea what to do or where to start. Nor did they know where to get help, how to find an architect/designer or general contractor, how to apply for permitting or where to find financing.

No one else appeared to be filling that information vacuum and dispelling the confusion surrounding the 2017 legislation. Once Bigelow’s business concept jelled, she founded Maxable, applying her online marketing skills to reach, educate and assist clients to navigate the ADU process and connect them with vetted professionals.

Bigelow, who now handles marketing and customer relations, launched the Maxable website ( in spring 2018. One of the first architectural designers she recruited was Jared Basler, known in the industry as the “Godfather of Granny Flats” for his deep experience converting and building accessory units and for his advocacy at the state and local levels for workable legislation and regulations. She brought Basler into the company as co-founder and lead designer, explaining that he “had designed and permitted more than 130 projects for Maxable and others and knows the ins-and-outs of the legislation, better than others in California.”

Interior designer Lydia Majette helped O’Shaughnessy implement her vision of a colorful interior.

Interior designer Lydia Majette helped O’Shaughnessy implement her vision of a colorful interior. Among her suggestions was painting all of the interior doors different bright colors.

(Jarrod Valliere / The San Diego Union-Tribune)

Basler, who trained at San Diego’s New School of Architecture and Design and now chairs the San Diego ADU Coalition, worked in construction before turning his focus on ADUs, explained that education is a large part of Maxable’s mission. He oversees the company’s design team and ensures that clients are matched with skilled professionals appropriate for their needs, with experience in their geographic area. Currently, Maxable works with about 20 design/construction professionals in the San Diego region plus others in the Los Angeles and San Francisco Bay areas.
“It’s all about making space livable,” Basler said. “Most homeowners don’t understand what goes into it and what they can do. We don’t want people to start a project and not be able to finish it.”

The city of San Diego, he explained, has been the most progressive in adjusting their policies to encourage ADU construction.

Outside the home, the team painted the stucco an identical sage green to match the existing exterior color.

Outside the home, the team painted the stucco an identical sage green to match the existing exterior color.

(Jarrod Valliere / The San Diego Union-Tribune)

Costs for a garage conversion now run about $100,000 — up from about $75,000 to $90,000 pre-pandemic because of material cost increases — and from about $150,000 for new detached ADUs, depending upon size, he explained. About 95 percent of all homes, including multifamily properties, are eligible to build ADUs, up from 5 percent before legislative changes.

Following a project assessment, Maxable works with clients from the project’s beginning, going over design options as well as bids and contracts, so that clients understand every step of the process, Bigelow said.

“We do design and permits and then connect homeowners to general contractors we’ve vetted in San Diego County so that they don’t have to find their own contractor,” one of the most difficult tasks for any construction job, she said.
“We’re going to help homeowners understand what they’re being charged and help from the very beginning to the end,” she added.

Most garage conversion projects take about nine months to complete from start to finish, though the pandemic extended those average times to about a year, Basler said, because of permitting staff disruptions and shortages of construction materials, appliances and equipment.

New large double doors in O’Shaughnessy’s granny flat open onto a new front deck at the home in La Mesa.

New large double doors in O’Shaughnessy’s 600-square-foot granny flat expanded natural light. They open onto a new front deck at the home in La Mesa.

(Jarrod Valliere / The San Diego Union-Tribune)

For an early project, Bigelow found a ready client for what turned into a demonstration project: her mother, Lynn O’Shaughnessy, an author and nationally prominent expert on college affordability who still lives in the La Mesa home, built in 1945, that she bought in 1991. O’Shaughnessy had turned the garage rental apartment into a writing office. Now she wanted to revive the apartment’s use for family visits or monthly rentals.

While the idea to convert the garage into a 600-square-foot granny flat was Bigelow’s, O’Shaughnessy proved an enthusiastic client, praising the general contractor they identified and the project management. O’Shaughnessy actively worked with Basler, her conversion’s designer, and brought in a friend, interior designer Lydia Majette of Raz & Majette Design in San Diego, to help her implement her vision of a colorful interior.

“How do you build an ADU and not make mistakes that cost a lot of money?” O’Shaughnessy asked.

She explained how, as part of the design and construction process, her general contractor solved long-pesky garage water leaks by locating the source of the problem and installing French drains. The team matched the style of the exterior to O’Shaughnessy’s existing home, painting the stucco an identical light sage green and giving it a compatible red front door.

The garage already had a vaulted ceiling, which they retained. They enhanced the unit’s natural lighting by adding a skylight and double glass doors opening onto a new front deck.

The living space provides ample room for guests as well as a workspace.

The living space provides ample room for guests as well as a workspace. O’Shaughnessy purchased almost all of the furnishings from resale sites and decorated with her own art and accessories.

(Jarrod Valliere / The San Diego Union-Tribune)

Both O’Shaughnessy and her daughter are enthusiastic recyclers of reusable materials and thrifty shoppers at yard sales and on online sites. For the granny flat conversion, they opted to reclaim wood salvaged from the garage rafters and repurpose it as well-seasoned shelving in the living room and kitchen. They purchased new appliances, including a single unit washer-dryer and a retro turquoise countertop oven. But almost all the furnishings, rugs, Fiestaware and even the succulents for the landscaping, O’Shaughnessy bought from online resale sites Craigslist or OfferUp. She decorated with additional art, pottery and other accessories from her collections, including a small hand-painted rocking horse made by Bigelow’s late father, Bruce.

“You can get great things on Craigslist,” O’Shaughnessy explained, pointing out the environmental benefits of reuse.

For the interior, Majette helped with selecting colorful Mexican tile for the kitchen and bathroom and recommended painting each of the interior doors and pocket doors different bright colors. She found the inexpensive African mudcloth-inspired floor tile from Floor & Decor that was used in the bedroom. O’Shaughnessy wanted generous storage, which resulted in 8-foot-tall closets with shelving.

For kitchen lighting, they continued the multicolor theme by selecting pendant fixtures suspended on multicolor cords from O’Shaughnessy ordered colorful fabrics from and had a local seamstress make curtains and other accents for the bedroom.

One of the first questions Bigelow and her Maxable associates ask clients is how they plan to use the new unit. If it’s going to be a rental, they recommend going with more durable materials. In O’Shaughnessy’s case, she uses it both for extended family stays as well as minimum one-month rentals.

Majette helped with selecting the colorful Mexican tile used in the kitchen and bathroom of the granny flat project.

Majette helped with selecting the colorful Mexican tile used in the kitchen and bathroom of the granny flat project.

(Jarrod Valliere / The San Diego Union-Tribune)

Many of her tenants are traveling nurses. During the pandemic, a couple fleeing Atlanta stayed with their dog for 2 ½ months. Because of the unit’s planned privacy, O’Shaughnessy rarely saw the couple.

Homeowners rarely consider hidden costs, Bigelow explained. These include demolition and site work prior to construction, as well as upgrading utility connections. Older homes, such as O’Shaughnessy’s, require upgraded electrical service.

“We recommend homeowners allow for a 10 percent contingency in these projects because there are always some unknown expenses,” she said, such as the extra $15,000 for O’Shaughnessy’s French drains.

Some costs can be offset partially by tax credits available for roof replacements, solar installations and upgraded electrical service. Maxable can assist with applications, Bigelow explained.

Bigelow and Basler are excited about the growth of the granny flat industry and look forward to helping expand the state’s affordable housing stock.

Building a granny flat on your property: one homeowner’s experience

When Felicia Shaw returned to San Diego in January 2020 after a stint working in St. Louis, she reclaimed the Azalea Park home she had rented to her son, whose family was ready for larger quarters.

She had bought the 1949 California bungalow with a detached garage on a double lot in 2008 and fell in love with the community within the City Heights neighborhood. The garage quickly turned into storage.

“My dream always was to convert it, perhaps to my ‘she-shack.’ It could be a wonderful rental property and provide a retirement income,” she explained.

Find out more about granny flats

For informative articles, a toolkit and other information about building an ADU, as well as a video showing the construction progress of Lynn O’Shaughnessy’s granny flat, visit Maxable at

Shaw had just started a new job as executive director of the Women’s Museum of California, within Balboa Park, and she knew she wouldn’t have time to undertake a construction project herself. She searched online for help with her project.

“The name that kept popping up for good people to work with as a reliable partner was Maxable. They were trying to educate people about ADUs and were giving away information on their website,” she said. Their site, she explained, offers numerous articles and guidance on everything you need to know about building an ADU, including a free toolkit to get started.

Maxable’s designer asked what Shaw wanted to do and then took care of the design and permitting, connecting her with financing sources and a general contractor, who is about to start work. She is enlarging her 400-square-foot freestanding garage into a 780-square-foot, one-bedroom granny flat, which she hopes to rent to an artist, writer or other creative.

In designing the apartment, she took pains to create a place she’d be happy living in herself.

“Building a granny flat at your home comes with great responsibility. You’re adding density. It’s a big responsibility,” Shaw said. “Maxable helps people do it the right way, not the cheap way,” she added.

Sours Larson is a San Diego freelance writer.