Thoughts on Minneapolis’ Proposed ADU Ordinance

Detached ADUs in Boulder, CO

Detached ADUs in Boulder, CO

Minneapolis folks, the draft ordinance for Accessory Dwelling Units is available! It’s like Christmas-come-early for urbanists. Ok, maybe not that extreme, maybe it’s more like President’s Day? I dunno. Either way, the pace that the city council and planning staff have moved this particular topic through to this point is very encouraging, as is the level of support (92%!) so far from Minneapolitans. That’s insane – I can’t imagine 92% of us agreeing on what color pavement our streets should be, so, good job!


Besides, we’ve already got ADUs (by form) capping many block-ends in the city. This just let’s us build more.

We’ve covered ADUs here only briefly here before, but there are tons of great resources to get yourself familiarized with the concept if you havent already. I took some time over the weekend to read through the draft, and wanted to get a few thoughts out there to make this foray into a new housing option as successful as possible.

A Realist’s Preface

I love ADUs. I want to build one in my backyard. But for all their positives, the realist in me can’t imagine them making a serious impact on the housing market. Look at Portland ADU permits by year (keeping in mind Portland has almost 3x the land area and an already 200k+ larger population than Minneapolis)



Yes, there’s been a jump recently after some policy changes, but we’re talking maybe a couple hundred a year, and less than 1,000 in existence in total. It could be a very long time before Minneapolis sees over 100 permit applications in a year. There’s nothing wrong with that. They can be tricky, expensive, and they need the right lot, location, occupant, personal finances in place to align, but they’re still a valuable tool in the “making Minneapolis affordable, walkable, etc” toolbox.

The Positives

First, let’s call the positives out. I think it’s safe to say that anything we end up with is better than not having ADUs at all, and Lisa Bender  + project staff have done an excellent job getting us to this point. The communication has been clear, and the process wide open with tons of meetings across city neighborhoods. Great job.

I also love that we’re not shying away from multiple forms of ADUs here. Allowing these new units to come from basement or attic space, an addition to a primary structure, or via a detached structure all give options and flexibility. Kudos.



The ordinance also encourages eyes on the alley via requiring 10% of the alley-facing façade to be windows. My gut reaction was “overly burdensome,” but the weekend made me re-think that. This likely won’t be hard to achieve, would have been done in most cases anyway, and really does have some positive benefits to keeping alleys safer (and beautifying them!).

Finally, parking! The behemoth that sinks any productive conversation for new development. I was pleasantly surprised to see that an ADU unit does not come with a requirement to provide off-street parking. The ordinance does require property owners to maintain the minimum parking spaces for the primary structure, which is fair. But exempting the ADU gives flexibility in design, lot placement, and cost for builders.

Room For Improvement

Despite all the positives, I believe there’s still room for improvement to the ordinance in a way that will still get this thing passed. I’m keeping the list fairly short to be pragmatic. In order:

  1. Floor Area – The ordinance keeps the lot coverage of a detached ADU to 676 square feet, or 10% of the lot area (whichever is greater). This is a seemingly arbitrary number that doesn’t really serve much purpose considering permeable surface area requirements by zoning district will remain in place. This seems especially ridiculous when you realize we’re limiting the amount of space available to house humans to the same number as storing cars. If we want to allow for flexible designs and retain owner parking, I suggest removing the maximum or at least making it a number that conforms to some design idea. An example could be: “total floor area can be 750 square feet if a single-story structure OR 800 total square feet with no more than 550 square feet on the ground level.” Just spitballin’.
  2. Height – As drafted, ADUs will be allowed to reach 16′ in height with 11′ high walls. However, 16′ is defined as the midpoint between the eaves and the ridge of the roofline (assuming this definition carries over from detached garage guidelines)
    RoofHeightsFor a hip, gable, or gambrel roof, this makes for a maximum ridge height of 21′. I’m sure this provides for some great designs, but it can still be quite limiting. My guess is most homeowners interested in building an ADU have a vehicle, if not two, and want to retain them. Units above garages will be a natural design fit, and a 21′ roofline with 11′ wall maximum could limit any number of designs that work well in other cities. Plus, it feels kinda bait-and-switchy after being shown designs in the (well-rendered) examples used at project meetings:


    Taller than 21′ on the right?

    Flat roofs should be allowed a full second story (20′), and pitched roofs should get more wiggle room (25′ max?) to allow for large enough habitable spaces on the outer edges where the roof slopes.

  3. Matching Materials – For detachedADUs, this could really hold back projects. Many existing homes don’t have all that great of materials, or conversely, have very expensive materials. We shouldn’t require a structure that will barely be visible (if at all) from the street to match the primary one. In fact, doing so could limit the architectural options and creativity that could really make our alleys more whimsical than today. As a point of reference, both Seattle, WA and Vancouver, BC do not require matching exteriors. As of October 20, 2014, they haven’t been reduced to pits of burning slag (right?).

    via SightlineDaily

    Different, but not necessarily out-of-place. (via SightlineDaily)

  4. Ownership Requirement – I’m not sure why this one made it in. We don’t require single family homes, duplexes, triplexes, or any other units that can legally be rented out to have owner-occupancy for one of the two units (the ordinance does allow the owner to live in the ADU). Why should we require this for ADUs? If we want to limit potential noise or disturbance to neighbors, we should regulate and enforce this the same way we do in other districts, not use some end-around method hoping an on-site landlord will be better.
  5. Exterior Stairs – I snuck this one in. It’s an odd requirement as, again, we don’t limit exterior staircases on multi-family units (duplexes, triplexes, etc). If the city is unwilling to budge on the height and floor area issues stated above (and the exclusion of new street-facing entrances for attached units), the least they can do is allow exterior stairs to maximize finished square footage inside the ADU.

Ok! I’m sure not everyone will agree with me. That’s fine. Use this post as a talking point to reach out to your councilmember. I can’t imagine 92% of city respondents supporting something the way ADUs have been. So before this thing gets passed and we feel like we can’t touch it again for more than a decade, let’s maximize that support to make some minor improvements. Thanks!

Alex Cecchini

About Alex Cecchini

Alex likes cities. He lives with his wife, two kids, and two poorly behaved dogs just south of Uptown (Minneapolis). Tweets found here: @alexcecchini and occasional personal blog posts at