Lot 22

Brit Builds an ADU: The Surveyor and the Height Problem

Hey! It’s been a while, huh? We are out of spring and well into summer, and our project finally is getting into the swing of things. I owe y’all a few updates.

Lot 22

A snippet of our surveyor’s work showing backyard elevation and our lot number.

When we last left off, we were concerned about what type of accessory dwelling unit (ADU) was possible on our property. So, we hired a surveyor (cost, about $1,600) to give us precise measurements of the property: where exactly our neighbors live and our height relative to sea level. It turns out, we are about 840 feet above sea level. Our house is a typical 1.5-story bungalow with an eave height of 852 feet and a peak height of 862 feet, so our peak is 22 feet above the ground!

Here’s what surveyors’ documents look like. 

ADU code says “(Detached) ADU cannot exceed the height of the principal structure or 20ft., whichever is less. The height point of the ADU’s roof cannot exceed the highest point of the roof of the main home

We’re good for two stories, right?! Our main house roof has a peak of 22 feet. But let’s re-read that first sentence. What is the height of our home? It turns out our home is not 22 feet tall. When you calculate the height of a single-family home with a gable roof, which ours has, you add the peak height and the eave height, then divide by two. For some reason.

So, our home is actually about 16 feet tall. That means that, without a variance, our ADU cannot be taller than 16 feet, even though this is 6 feet shorter than our roof peak — at which height you wouldn’t be able to see the ADU from the street behind the main house anyhow. A 20-foot height restriction is already somewhat short for an ADU over a garage. Single-family two-story homes can be as tall as 28 feet by right even in R1A, the most restrictive zoning district in Minneapolis. And remember, all of these heights are peak heights; the roof of the ADU cannot exceed them.

So, what are we going to do? If we stick to the 16-foot height and don’t request a variance, we cannot build a second story, and this is just going to be a weird garage with some offices. No ADU, no additional income to offset mortgages, no ability to help house family, friends or neighbors. No comp plan needed. After all, there’s no benefit to low-intensity infill, right? No.

Instead we will be asking for a variance for a 20-foot-tall ADU, which is just enough to build the space we want so long as we have a flat roof.

A flat roof? Won’t that be terrible for winter? Eh, our architect reminds us that the commercial buildings around here get by just fine. And a modern/contemporary building will be a nice offset to our more traditional post-war stucco home. Plus, it gives us plenty of space to stick some solar panels on top and help offset some of our electricity costs and carbon footprint. Yea!

But, wait a minute . . .

This height restriction really is a problem. (Is it for aesthetic reasons? I don’t understand.) If we are saying not only that ADU’s cannot be as tall as a typical two-story home (20 feet vs. 28 feet), but must also be shorter than the main/street-facing home itself, this means that a large proportion of the homes on my block cannot build an ADU and have a garage. The main floor of an ADU cannot exceed 676 square feet. The total square footage cannot exceed 1,300 square feet, including the garage or other non-living space.

Additionally you may have only one accessory structure — whether it’s a dwelling unit or not — on your lot in addition to your home. Technically if you have a shed and a garage, you may be violating the zoning code. Our home is 1.5 stories and clocks in at 16 feet. My block alone has about 11 homes that are as tall as or shorter than ours. Why should some homeowners have more rights to building more homes on their property simply because they chose a larger or smaller home appropriate for their neighborhood and lifestyle?

A bungalow is a beautiful house to live in, and adding an ADU to the property increases the property value and provides all that lovely flexibility we talked about at the beginning of this series. This code encourages teardowns replacing these lovely, small older homes simply because you would improve your property rights for an ADU by removing an older home and building a City McMansion, thus increasing the potential ADU height and value.

Currently the city is considering variances as a solution to these issues. Variances add uncertainty, time and expense to the homeowner and cost the city time on its docket. But variances are useful in cases where discretion is needed or the choice has the potential to intensely and unfairly impact neighbors. On the other hand, we could change the height restriction entirely while we’re reviewing it for the 2040 Comprehensive Plan changes.

I’m fine with having a height restriction on ADUs. It makes sense that people might not want a 2.5- to 3-story (typically 33-35 feet) tower on a tiny piece of their neighbor’s lot. But given the already limited square footage, a simple maximum height limitation in line with existing two-story homes makes a lot more sense and would allow homeowners to build a wider variety of spaces appropriate to their needs and roof preferences.

Brit Anbacht

About Brit Anbacht

Brit Anbacht is a millenial policy wonk and general nerd. They work from home full time. Brit sometimes drives but ever more frequently takes the bus for errands. They live in south Minneapolis, and can be found occasionally on twitter @britvulcan.