On July 17th, Historic Denver hosted a tour of ADUs (Accessory Dwelling Units) in the Curtis Park Historic District. “Accessory Dwelling Unit” is a technical term that refers to any additional living space on a lot other than the main dwelling. So if a single family home has an in-law unit added in the basement, that’s an ADU. If the space over a garage is fixed up to be a separate apartment, that’s an ADU. If a mini-house is added in the backyard behind another house, that’s an ADU. Essentially any added living space with its own entrance, its own kitchen, and its own sleeping area on a lot that already has a house is an ADU.

ADUs, especially those built into already existing buildings — whether as part of the original house or as part of an existing garage — are a way to add density (more people per square mile) to a neighborhood without expanding the boundaries. In neighborhoods that are seeing strong development pressures to scrape buildings and replace them with apartment buildings, ADUs can be a sensitive way to add places for people to live without wiping out the history, culture, and character of the neighborhood.

The former Sacred Heart School now hosts Sacred Heart House, which provides temporary housing, food and clothing for homeless families in Denver.

Historic Denver’s tour was a part of their bi-monthly Re:Denver talks which address various urban development topics with an eye toward preservation. Issues tackled in the past include affordable housing, the neurological impacts of buildings, changing landscapes, and the environmental impacts of demolition vs. deconstruction. The presentation on ADUs gave attendees the opportunity to visit four units within the historic Curtis Park neighborhood. After meeting in the historic Sacred Heart School for a brief presentation, the sizable crowd was divided into four groups, each of which set out to begin their tour at a different ADU.


Adaptively Reused Horse Barn

The first ADU I visited was formerly a horse and carriage barn. It had fallen into severe disrepair, but when the current owner first climbed the ladder to check out the hay loft, her first thought was “Someone could live up here.” The old barn was adapted to become a small apartment with a bathroom, kitchen, laundry and living room on the first floor and a bedroom plus a second bathroom on the second.

A gable dormer was added to one side of the roof, just wide enough to accommodate a twin bed. A very small shed dormer was added to the other side to add head space at the top of the stairs that were built into one side of the barn. (The gable dormer is visible from both inside and out in the images above. The shed dormer can be seen in the upper left photo in the image below.)

The property owner is an artist who has added murals to her garage doors just one lot over. (See photos at upper right and lower left above.) The exterior of the old barn was re-clad using salvaged barn wood from another site. Glass bricks provide light into the downstairs bathroom. (See lower right photo.)


Interior ADU

The second ADU we visited consisted of the second story of a beautiful Victorian era house. Each bedroom had its own fireplace, there were original gas lighting fixtures in place (though they were not in use), and the separate entrance included a sizable entryway on the first floor.

By creating a second dwelling unit in their house, the owners, an older couple, are able to remain in their own house while expanding their income. By retaining the first floor for their own use, they greatly reduce the frequency with which they’ll need to use the stairs, an exercise which only increases in difficulty with age.


A Brand New ADU

In cases where the original house is too small to subdivide, and there are no usable structures in the back yard to convert into habitable space, a new structure might be an option. The third ADU that we toured was still under construction. Though taller than the house it shared a lot with, the teeny lot widths (There was about 3 – 4 feet between houses in this part of the neighborhood.) meant that the new 2-story house couldn’t be seen from the front of the older house, so it didn’t detract from the character of the street.

This last ADU that we visited (Unfortunately we didn’t have time to visit the fourth.) had a fairly spacious 2-car garage on the ground level with a 1-bedroom apartment upstairs. The living room was surrounded with large windows that provided an excellent view of the alley (which wasn’t much to look at) as well as a pretty decent view of downtown Denver.


Curtis Park Historic District

Map of the Curtis Park Historic District

The historic district in which all of these ADUs were located was formed in 1995 and is one of the oldest remaining residential neighborhoods in the city. In a 2016 report about the character defining features of the district, carriage houses (a phrase commonly used in place of ADUs) were noted as one of those character defining features.

Though Fort Collins does have some ADUs in Old Town, the addition of new units is limited to certain zones and lot sizes.