Is your Colorado property zoned for an Accessory Dwelling Unit?

Posted by West + Main Homes on Thursday, March 29th, 2018 at 10:35am.


Photo courtesy of venidami

Accessory Dwelling Units (or ADU's) are a popular topic amongst West + Main agents and our clients.

Even so, we understand that many people do not understand why ADU's (also sometimes referred to as Granny Flats...more on that later) are so important in Denver's housing shortage -- and why we think that they offer at least part of a solution.

Denver certainly isn't alone at the forefront of this movement...cities like Portland, Seattle, and Austin are also seeing its residents constructing, fighting for, and thriving in ADU's...so let's start there:


From "The Granny Flats are Coming" on CityLab:

When Kol Peterson moved to Portland, Oregon, in 2010, affordable housing was a priority, as it was for many newcomers in this city’s booming real-estate market. He looked at two frequently discussed options for high-cost cities—tiny houses on wheels and communal living—but decided on another option: accessory dwelling units, or ADUs—also known as granny flats, basement and garage apartments, and the like.

ADUs weren’t yet common in Portland—that year, the city issued only 86 permits for them—but when Peterson did the math he decided that building one was his best option. “I could buy a house, construct an ADU in the backyard, and live in the ADU while renting out the house,” he said. That’s what he did: He bought a home in the city’s King/Sabin neighborhood, built a tidy two-story mini-home in its backyard, and moved in. The experience, he says, has been life-changing. “Building an 800-foot ADU eventually eliminated my housing costs, and I’m living in my dream house.”

Eight years later, Peterson works full-time helping others build ADUs, preaching the granny-flat gospel via classes for other Portland homeowners. The number of ADU permits the city issues has risen dramatically; in 2016, it was 615. In Vancouver, Canada—an ADU pioneer—more than 2,000 ADUs have been built citywide in the last decade. But for most cities in North America, steep legal barriers are preventing this form of housing from taking off: Many cities ban them outright, and those that don’t often have severe restrictions on size, owner occupancy, and parking. Only a handful of cities have adjusted their regulations to encourage more ADUs—mostly on the West coast, where severe housing affordability is a growing problem. But Peterson and other ADU advocates are predicting that the country is on the verge of welcoming more of them.

“By 2020, ADUs will take off in tens of cities,” he said. “This doesn’t mean there will be an explosion of them overnight, but the concept will become more popular in the next couple of years.”

Peterson has now parlayed his ADU expertise into a new book, Backdoor Revolution: The Definitive Guide to ADU Development, that walks potential ADU builders through the planning and construction process, as well as tackles the social, economic, and environmental issues that relate to such housing. CityLab spoke with him recently about why ADUs are gaining traction and how to advocate for making them easy to build in your city.


Photo via Flickr.

There’s a lot of single-family zoning in the center of our cities, and urban planners, civil society, and city leaders are questioning whether these zoning rules make sense. We’re missing dwellings that can house more people and are more affordable, such as duplexes, triplexes, and ADUs.

I don’t think tiny houses on wheels will soon become a widespread form of housing, because they aren’t yet permittable. But media coverage of them has helped to spur more interest in small housing in general. These factors are positioning ADUs to become a popular movement.

What are the benefits of ADU's for residents, cities, and the environment?

ADUs allow people housing flexibility over time. You can design an ADU in which to age in place, and then rent out your main house, allowing you to stay in your neighborhood as you grow older, and at less cost. Parents, caregivers, or adult children can also live in ADUs.

ADUs use fewer resources like gas and electricity due to their size, and because they’re often built in walkable and bikeable areas, their residents generate less of an environmental impact that way as well. They also reduce the per capita residential footprint. This is important because there are a lot of one- and two-person households in cities, but not the housing to match that demographic. ADUs can help fill this need.

And ADUs generally don’t have a significant infrastructural impact on a city, in contrast to, say, a 400-unit apartment building. They bring more housing to an area organically, and the city doesn’t have to build new infrastructure to accommodate it.

Read the rest of this piece on CityLab to learn more about where ADU's are growing in popularity.

So, will carriage houses (or ADU's) solve the housing shortage in Denver? Not on their own, but we think they are certainly a step in the right direction.

In 2010, a zoning change allowed ADUs in some Denver neighborhoods based on a number of factors, including community desires. The idea of squeezing low-rise, small-scale affordable housing into existing single-family neighborhoods is very popular in the world of affordable housing theorists, and what’s not to love? Homeowners get an additional source of income, renters get more options and neighborhood character doesn’t change as dramatically as when single-family houses are scraped for mid-rise apartments.

Read more about how many ADU's have been built in Denver.

If you are thinking about building an ADU on your Denver or Colorado property, the place to start is to find out if your property is properly zoned to accommodate an ADU.

In Denver, start here.



West + Main agent Kassidy Benson is passionate about ADU's and Denver's city neighborhoods. She is hosting a class on April 5th to answer questions and help local residents explore the possibilities of ADU's...and you are invited!

"I believe in 2018, you will see this concept become more mainstream and cost effective to build. This is going to lead to heavy investment in neighborhoods zoned for ADUs," 
- Kassidy

Let Kassidy know if you have questions or would like to attend!

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