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Minneapolis begins to see the benefits of ‘granny flats’

“Wouldn’t it be great?” Carol Roth exclaimed. “We don’t have extended family in the area. Wouldn’t it be great if we had close friends living with us who could be like an extended family?”

Carol owns a duplex in South Minneapolis, and was telling me about her dream of someday turning her empty 2-car garage into an apartment where her good friend Marne Gerdes might live.

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“Marne was the first person we thought of, because she gets along with our children and our dog. Our friends have become our extended family, and one of the options is converting garages. But it’s something I found out is not currently legal in the neighborhood. Maybe someday,” Carol sighed.

Minneapolis’ expanding ADU trial

In planning jargon, the apartment Carol was describing is called an ADU. It stands for accessory dwelling unit, and it’s an old idea with many names: “granny flat,” “in-law unit,” “attached cottage,” “carriage house” or simply “basement apartment.” Think of a garage or an outbuilding converted into separate living spaces.

Unfortunately for Carol and Marne, ADUs generally are not allowed in Minneapolis. But the good news is that Minneapolis is considering the idea of allowing more ADUs throughout the city.

Since 2001, ADUs have been permitted in part of the city’s Phillips neighborhood. (But because of high costs, and generally low real-estate pressure in that neighborhood, very few of them actually have been built.) And some are legal but nonconforming — essentially grandfathered.

MinnPost photo by Terry Gydesen
Council Member Lisa Bender

Now there is a proposal to expand the ADU trial to the rest of the city. Ward 10 Council Member Lisa Bender is one of the key voices behind the idea; she  explained to me that ADUs can provide more flexibility for property owners.

“We’ve had a lot of interest in ADUs from different stakeholders,” Bender said. “This is a way of increasing housing options within neighborhoods. It gives property owners more flexibility of how they can use their home. For example, having an extended family member live there, or moving into a smaller unit after retirement and renting out the bigger property. It’s a way for people to be able to stay in their homes.”

Demographics are changing. Families are smaller. More single people rent apartments well past the age of 30. And many people in the aging baby boom demographic are looking to downsize high-maintenance homes. At the same time, cultural tastes are changing. More young people and families are attempting to live with fewer cars, and live/work spaces are becoming more common as traditional 9-to-5 jobs disappear.

The carriage-house precedent

While ADUs might sound revolutionary, they’re hardly a new idea. For example, if you live in St. Paul for long enough, eventually you meet someone who lives in a carriage house behind one of the many Victorian mansions that line Summit Avenue. St. Paul’s many old homes used to house extended families, their servants and, in stables on the property, their horses. Nobody keeps horses in the city any more (and for good reason!),  and today many of those old stables have been converted into separate apartments fronting the alley.

MinnPost photo by Bill Lindeke
A carriage house off Summit Ave. in St. Paul

I reached out to people in Minneapolis and St. Paul who live in carriage houses, and found that many people seem to like them.

For example, Sheila Regan lives in a Minneapolis carriage house with her boyfriend, and loves it. “It’s kind of hidden away so there’s lots of privacy,” Regan told me. “It’s two bedrooms, and about the same price I would pay for a two-bedroom apartment. We also get a little patio. It feels more ‘adult’ than living in an apartment building. Plus, we get to play music as loud as we want because no one can hear it.”

Likewise, Susan Gray has lived in a St. Paul carriage house for years, and shares Regan’s delight about the privacy. “The best part of living in a carriage house is you don’t share walls with another person,” Gray explained. “On the other hand, carriage houses tend to have some awkward spaces. My landlord has listed the place on the market since I’m moving south — you can see there’s slanted ceilings and I’ve knocked my head a time or two.”

At the same time, carriage houses often have difficulties conforming to existing zoning codes. Mary Moreira lived for years in a “mother-in-law apartment” above a Minneapolis garage. There was one small problem.

“It worked very well,” Moreira told me. “But in Minneapolis, zoning would not allow me to have a kitchen. I ended up with a microwave and a toaster oven, which wasn’t too bad, but I would have liked a real kitchen. Also, the only way in Minneapolis that you can have water in the ‘apartment’ was if it was an attached garage.”

MinnPost photo by Bill Lindeke
A carriage house off Maiden Lane in St. Paul’s Cathedral Hill neighborhood.

Potential problems and Portland data

According to Shanna Sether, a planner for the City of Minneapolis, the main roadblock to ADUs is Ordinance 535,190, which prohibits more than one residential structure per zoning lot. And like the kitchen and water problems, there are a bunch of other difficulties with how city codes govern ADU units, rules that make it all but impossible for owners to build them.

According to my research, there are a few common objections to allowing ADUs throughout the city. Neighbors worry about how ADUs might affect property values, and remain concerned about parking, traffic and overcrowding in neighborhoods. Here in Minneapolis, another key concern: Neighbors worry that ADUs might increase the likelihood of absentee owners neglecting their property.

But if results in other cities are any indication, concerns over the traffic and quality of life impacts of ADUs might be overblown. Portland, Oregon (that mecca of innovative American planning ideas), is one of the few U.S. cities to actively encourage ADU construction, and more than 800 ADUs of many different sizes and shapes have been built there over the past decade.

Earlier this year, the Oregon government released a study of how ADUs have been functioning in Portland [PDF], and found a few surprising conclusions. Despite their lack of an owner-occupancy “homestead” requirement, 64 percent of Portland ADU arrangements were occupied by the owners. Similarly, ADUs were found to have a lower-than-average impact on parking and traffic congestion in neighborhoods where they were constructed, about the equivalent of an apartment near a transit line.

One reason for the differences is that ADUs almost always have a do it yourself (DIY) quality, where property owners act as their own developer, designing and contracting a new apartment by themselves. That tends to create a more intimate relationship between the renter and the property owner, which is one reason family members and friends so often move into these kinds of units.

Growth without big new apartments

In her first state of the city speech, new Mayor Betsy Hodges shared an ambitious vision to increase the city’s population past 500,000. Most planners agree that achieving that goal is going to require lots of new construction along key transit corridors. But if recent debates in Uptown are any guide, new buildings are often fought by neighbors, particularly if they involve tearing down existing structures.

Instead, ADUs might allow our cities to grow without demolishing older homes. “This is a great way to add a lot of housing options within neighborhoods spread out across the city, rather than larger multi-unit buildings,” Council Member Bender told me. In other words, ADUs might help Minneapolis’ density grow more slowly and organically no matter what neighborhood you might be living in.

If Minneapolis’ experiment with “granny flats” goes well, maybe Carol and Marne’s dreams will come true. Public meetings (Aug. 12 and 23) begin next month! Be sure to bring your mother-in-law.

Comments (10)

  1. Submitted by Janne Flisrand on 07/23/2014 - 10:53 am.

    Reinforcing current neighborhood character

    One of the things I enjoy about these kinds of apartments are they they slide so easily into our neighborhood character, neighbors don’t even notice them. I was at a gathering at a friend’s recently where, once we got into the back yard, we found a carriage house. From the street — and it’s a street I’ve been using for 18 years — there’s no hint of the back-yard home.

    If we want to grow the city (and I do), this helps owners afford their properties and taxes, and preserves that single-family neighborhood character Minneapolis and St. Paul rave about.

  2. Submitted by Constance Sullivan on 07/23/2014 - 12:27 pm.

    There are details to be clarified before we all just jump on the “granny flats bandwagon.”

    First, there are space requirements that take into consideration that most single-family homes in Minneapolis are not mansions with carriage houses, on the large lots that would permit them. They’re lots of 40′ by 132′ or so, for the most part, and one asks: what size of a garage, taking up how much or little of the lot, does one need for a legitimate, viable “granny” apartment tacked on?

    Then, there are the longer-term consequences in turning single-family property into a single-family house and a “flat” out back. Once you age, and your friendly extended-family garage renter ages out of your sweet situation, what happens to the property? Maybe you, or a subsequent owner, will rent it out. To whom? Will there be knowledable, responsible, landlording?

    We should pay attention to WHY north Phillips has not seen a plethora of these accessory dwellings. It doesn’t seem that anyone has really looked at this, apparently failed, experiment in Minneapolis.

    Maybe we could require that the property already have a mansion on it, plus a carriage house–not a garage for one or two cars.

    Really, folks, this sounds a bit like the “oh, wow!” thing that got us Uber and Lyft and looser taxi regulation–innovation for the sake of it, with little real reflection on the public policy implications.

    • Submitted by Alex Cecchini on 07/23/2014 - 01:35 pm.


      The faux concern for people living in ADUs is palpable. I lived in a 7′ x 13′ single dorm room in college. Throw in a bathroom, maybe even a small kitchen. You’ve got, what, 150-200 sqft? I stayed in a VRBO in London, place was a 10×10 bedroom with a 4×4 kitchen (with combo washer dryer) and a bathroom maybe 4 x 8. My wife and I both survived just fine, and I would imagine for the right price, many people in Minneapolis would, too.

      We have a house on a 40′ x 130′ lot in Minneapolis. It is not a mansion (800 sqft foundation), and it has a 2 car garage in the back yard. I am strongly supportive of this, and would more than likely tear down my garage the minute it needs a new roof to build a new one with an attic apartment in it (the exterior isn’t in great shape, nor is the concrete slab, so the costs of a new structure would only be in addition to the repair costs). Why would we want to require this for only mansions with carriage houses on the lots?

      Do we have the type of landlording requirements you’re concerned about for duplexes, triplexes, or even single family homes owned by a landlord and rented to a stranger? Why treat ADUs any differently?

  3. Submitted by Bill Lindeke on 07/23/2014 - 01:10 pm.

    I’d imagine it would be …

    I’d imagine it would be like duplexes? There are many duplexes all over the city. I was talking to a friend of mine who just bought one in Powderhorn, and is looking for friends to rend out the bottom floor. I know of many examples like this in all parts of the city.

    Good question about the north Phillips neighborhood! It’s worth noting that it’s one of the poorest neighborhoods in the city. I think that many ADUs in Portland have been built in neighborhoods with higher demand, and thus more incentive for a property owner to invest money in improving their home with an ADU.

  4. Submitted by Michael Hess on 07/23/2014 - 01:26 pm.

    Not for every one or every lot

    I like the idea of legalizing these type of residences providing they fit – so just like any change to the code the city would need to ensure the lot was big enough to support another residence and it’s integration to the lot fit. For example with the 2 story garages we now allowed to build you need to match roof pitch and exterior material to your house. If this works for you great, if not, well build a normal garage.

    I think it’s a mistake to assume the experience in Philips is a “failed experiement” – this is a supply and demand issue and if there is not a high demand for additonal housing units in Phillips why would you spend so much to create a new one? It’s obvious that it will cost more to create one unit of housing this way then it would a mult-family dwelling – you need to get utilities trenched and extended from the main house to an accessory house, you need mechanicals….. they will get built where the owners can afford to make the investment or in parts of the city where rents will make it worthwhile. It’s not going to work automatically everywhere and it’s quite frankly foolish to assume it would go that way.

  5. Submitted by Erica Mauter on 07/23/2014 - 06:10 pm.

    What’s the incentive…

    … to build new ADUs where there are not existing ones? What’s the demographic of homeowner that would be targeted here?

    And I wonder, if you already have problems in some parts of town with the size of a new construction house relative to the one that got knocked down, how do you also manage the scale of ADUs?

    I’m fairly certain an ADU has been built in the last year at a house at the corner of W 47th St and Colfax Ave S. Can’t tell if it’s occupied, though.

    • Submitted by Alex Cecchini on 07/24/2014 - 09:10 am.


      The incentive is to rent out space and make money over the initial investment. The demographic of a homeowner would be anyone who has the need to rebuild a garage (which provides a ripe opportunity), is re-evaluating their personal finances, re-evaluating their personal space/storage needs, and/or any other legit reason. I don’t like the term “granny flat” or “mother-in-law” apartment because it somewhat frames the discussion around people building these only for relatives while also steering the discussion to “primary structure must be owner occupied.” Yes, allowing family members to age in place or to provide flexibility to extended family/friends is one piece of the ADU benefit puzzle, but personal financial stability via rent is a major component as well. I’m willing to give up the parking pad outside my garage, as well as rafter and interior storage to build a second story apartment and bring in potentially many thousands in rent profit per year.

      Why does the issue of scale need to be managed? People complaining about new houses being “out of character” with existing ones forget the incremental process by which neighborhoods evolved for a thousand years before we locked scale/”character”/use in via zoning by block or neighborhood, and it’s flat out a form of regulatory capture. If building an ADU provides me personal or monetary utility, why should we try to regulate that? Since access to light, air, and privacy are not constitutionally guaranteed rights, if my neighbors dislike the new scale of structures, they can compensate me in exchange for my loss of utility (similar to purchasing air rights).

  6. Submitted by jody rooney on 07/24/2014 - 11:10 am.

    I am a big fan of the “granny flat”

    There is a pretty interesting design book on the flats:

    In-Laws-Outlaws and Granny Flats by Micheal Litchfield

    This isn’t the same cover as the one I have so I don’t which is still packed away but it is pretty inspiring.

  7. Submitted by Darielle Dannen on 07/25/2014 - 11:28 am.

    I Like it!

    Like many in their late 30s I have two sets of aging parents, with a mother-in-law who has serious health issues. My husband and I have a home on two Minneapolis lots so we are blessed with space! We would love to have the option of building a granny flat over the garage if/when our parents need more assistance in their lives but can still maintain a separate space. It would be a blessing to have tea with the parents in the morning before work, and jointly cook dinner together at night without having to worry about their drive back to their own home – which is fairly fraught with danger as only my father-in-law can drive at this point and he is fairly blind in the dark. It seems like requiring the home to be homesteaded and limiting the square footage of the granny flats would allow those of us blessed with space in Minneapolis to use some of it so our parents can age more gracefully and safety without compromising the character of our neighborhoods or causing parking congestion.

  8. Submitted by on 10/09/2014 - 07:29 am.

    Granny Flats

    I love granny flats as it very comfortable to live in. Recently I saw many great designs of granny flats here

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