Diane Owen’s ADU: A Carriage House at My Daughter’s Place

Editor’s Note: This post is an extended case study from the AARP ABCs of ADUs publication published earlier in 2019. The first post was Walt Drake’s ADU: A Father-in-Law Unit in My Own Backyard and the second was Bertha’s ADU: A Tiny Cottage in my Son’s Backyard. Stay tuned for additional extended case studies from this project in the coming weeks.

Quick Facts

• Owner Name: Mara Owen
• Tenant Name: Diane Owen
• City & State: Denver, Colorado
• Designer Name: Hive Architects
• Builder Name: Hive Architects
• ADU Type: Apartment Over Garage
• Year Built: 2016
• Square Footage: 360
• Cost: $167,000 

“I see our carriage house as something very similar to a student loan. It’s something you invest in the future with. It was cheaper than buying a house in Denver for mom, and it lets her have independence. It’s great knowing we can check in on her whenever.”

Mara Owen

A few years ago, Diane Owen was sharing a house in Denver, CO with her daughter Mara, and Mara’s partner Andrew. Diane’s one bedroom, one bathroom multi-generational household also included three dogs, so it was a full house! Diane had been living with Mara and Andrew for three years and they got along really well, but there were moments that a little more wiggle room would be nice. 

“We have a good relationship, but it was hard before when we didn’t have our own space to be our own people. It was just the stupid little things that are hard with any roommate, even if it’s your mom. ” 

Mara Owen

However, every time she considered moving, Diane was confronted with the reality that on her fixed income she wouldn’t be able to buy a place of her own in Denver. Moving meant she’d need to move farther away from family, which didn’t make sense to her at this point in her life. Additionally, if she rented she’d have a difficult time finding a place in her price range that would allow her to live with her two dogs, who provide great companionship to her. Fortunately, Diane’s family landed on the solution when her daughter Mara’s fascination with ADUs and her career as an urban planner intertwined.

“I remember thinking ADUs were really interesting,” Mara explains. “I was familiar with the idea of carriage houses because I liked to watch old movies, like Cary Grant. I like the old architecture and style of carriage houses, but I also liked that they created a way to have family or friends nearby. As a nerd, going through City of Denver’s zoning codes, I discovered an ordinance in 2010 about ADUs and realized they were like the old carriage houses in the movies. Since mom was living with me, I saw a carriage house as a cool opportunity to give her her own space.” 

Mara Owen

Once she recognized that it was possible to create ADUs in Denver, Mara learned everything she could about Denver’s ADU ordinance and explored the types of ADUs they could create. They determined that their best option would be to remove their “leaky and defunct” garage and build a new garage with an apartment above it. They wouldn’t be able to use the footprint of the existing garage when they rebuilt because the garage had been located on the property line. However, they determined that even once they honored the 10’ setbacks on both sides of the property, they’d be able to build a carriage house that was approximately 350 square feet above a new two car garage. They decided to match their new garage to the look of their house.

“We personally chose to match the house. I don’t think there’s a requirement, but I like my current house and thought it would look cool if they matched.” 

Mara Owen

Diane and Mara worked with Becky from Hive Architects as they began defining their design criteria. They’d selected her after interviewing several architects. Mara had looked up questions and asked the same list of questions of each of the several architects they interviewed. 

“Get a really great builder and architect. Interviewing architects was similar to a first date. It’s not just who you feel connected with. That’s important, but get to the values. It’s a niche market, so see if you can find someone who has built ADUs before because they are a little different. Ask them why they are doing ADUs. When we came to the harder stuff she was on the same page as us.”

Mara Owenr

It was important to all of them that Diane’s carriage house feel airy and open as well as connected to the primary dwelling via the yard. Safety was a consideration because Diane’s unit was located off the alley and there wouldn’t be as many people seeing her come and go. They wanted to ensure that Diane would feel safe coming into her home and they wanted to provide parking for each of the units. They accomplished both by dividing the garage with a wall down the middle and providing a door from Diane’s garage to her apartment. As they designed the carriage house, Diane and Mara also considered how they already interacted and how they wanted to interact with the addition of the new living space. 

“We were living in same house for a long time, so we already knew we live well together, but we also knew what would make us happier. Mom’s place needed a dog door and dog run so I wouldn’t have to worry about dog poop in my yard. Also, the dog door allowed her to not have to take the dogs out two times a day, so she could just let them roam around where they wanted all day. Mom loves being outdoors and airy open spaces, which my house, built in 1917 was not so good at. So we made sure to add a ton of windows to the space so she could feel like she was outdoors, even when she isn’t. We also designed the kitchen around mom’s cooking habits, and the bathroom was designed with a heated towel rack since she hates wet towels and would always put them in the dryer after taking a shower.”

Mara Owen

Universal design was a key criteria for Diane’s carriage house. They designed the stairs wide enough to have a chair lift go up them eventually. The shower is wide enough for a bench. Door handles are levers rather than knobs. Diane decided not to add all the grab bars for aesthetics, but the blocking is in the walls so that they can be added as necessary. 

Diane and Mara were also mindful about including several sustainability features. They used an energy-efficient mini-split heat pump for both hot and cool air and installed an on-demand water heater. The carriage house is all electric, with no gas appliances or furnace. It is also solar ready; when the family has saved up for solar panels, they can have an array installed. 

“The roof is set up at right slope and we had it looked at by solar panel people. We can fit an array of panels on the south side and that can connect into the whole system. Since the ADU was designed to be energy efficient with good insulation, insulated garage doors, high insulation windows, and the entire thing well sealed, hopefully it can sustain itself.”

Mara Owen

During the design process there were three primary challenges. First, financing the project was a stretch. Mara took out a Home Equity Line of Credit (HELOC) and her siblings contributed financially with personal loans. The family pieced together their financial package with a Home Depot credit card and two other credit cards to cover the full amount, which they paid off as quickly as they could after the build was complete. This financial investment made sense because it was more affordable than other options and it allowed Diane to remain near her daughter.  

“Mom wouldn’t be able to live anywhere near us if we didn’t have the ADU. Knowing she’ll have a limited income, we’re glad we can help subsidize her housing, which is her largest cost. She didn’t have a retirement plan, so we’re making it for her with this ADU.”

Mara Owen

Their second major challenge was that their project required a variance due to their lot size. Mara’s house is located in a zoning district which allows ADUs on lots that are 5,500 square feet or larger. No one anticipated this would pose a problem because most of the lots on the block were this size. However, when they had the property surveyed they discovered that the fence wasn’t actually on the property line. Mara says “we thought it was our property, but it turns out the historic fence was built in the wrong place.” 

Fortunately, their designer, Hive Architects – who also general contracted the build – had worked through the variance process before with the  Board of Adjustments in Denver.

“Becky is an advocate in Denver and she walked us through the variance process. She was integral in saying it will take a long time and I’ll help you go down that road. She was absolutely fantastic and we wouldn’t have been able to do it without her.” 

Mara Owen

The final challenge was that, in order to move into her 360 square foot ADU, Diane needed to downsize. Fortunately, as they designed the ADU, Hive Architects tucked in as much storage as possible. The way the ADU is designed it has low headroom on both sides where the roof meets the walls. That area where it’s too low to stand is dedicated to storage. Additionally, since she was living in her daughter’s house Diane could leave some of her furniture there. For instance, the dining room table that belonged to her grandmother is in use at her daughter’s place. Meanwhile, the space that Diane had occupied in Mara’s house has now become an office for Mara and Andrew.

Now that Diane has her own place, interactions between her, Mara, Andrew, and the kids are still frequent, but they’re more spacious. 

“We say ‘hi’ every day and we don’t need to give Mom a phone call to keep up with her life. We still share dinner once in a while. She watches the house when we’re out of town. We don’t have to have a babysitter or dog sitter and we don’t have the stress of who didn’t do the dishes.” 

Mara Owen

The family plans to use the property in this configuration for as long as it works for everyone.

“We did plan it so Andrew and I could live there if mom isn’t there for any reason. We would be happy living there and maybe my sister or brother would live in the house. It could be a family complex.”

Mara Owen

For Mara, being able to create a living space and have it designed exactly how Diane wanted it, was the highlight of the project.

“I’ve always loved being able to make something. I love being able to reach here and turn on light switches that we put here because this is where it’s most convenient, this is where it should be.”  

Mara Owen

So what advice does Mara have for someone considering creating an ADU for a family member on their property? 

“Go for it. I can’t think of a reason why it would be a bad thing. You have so many advantages by creating an ADU. There’s a myriad of uses and everyone has someone in their life they could help out. We had the option to be more caring to people around us because we had the space to be caring. I hope other people do it, too!” 

Mara Owen

About linamenard

Hi. My name is Lina Menard and I'm a small house dweller, designer, blogger, and builder. I'm currently collecting ADU Case Studies for AccessoryDwellings.org. Through my company Niche Consulting LLC, I help people design and build the home (and life) of their dreams! I also tell my stories about simple living in small spaces - like a travel trailer, a yurt, a backyard cottage, and tiny houses on wheels - at Niche News.

View all posts by linamenard →