Accessory Dwelling Units (ADUs): A Tool for Preservation


Minneapolis is growing. For the first time since the 1970s, the population has reached more than 400,000 people, and folks are struggling to find places to live. There’s a lot of economic pressure to demolish old homes and develop apartment buildings and condominiums to make space for these new residents. This influx of people threatens to harm the unique neighborhoods that attracted them in the first place. But there’s another way forward.

The City Council is considering allowing accessory dwelling units (ADUs) in Minneapolis. They’re also known as granny flats, mother-in-law apartments, and carriage houses, but ADUs are essentially self-contained living units on the lot of a single-family home. An ADU could be detached from the main structure, attached, or internal (like an attic apartment). ADUs have been cropping up in cities like Seattle, Portland, and Denver in recent years.



Making preservation economically viable

People demolish old buildings not because of any animosity toward preservation, but as the result of an economic calculation. Allowing ADUs would change that calculation in favor of existing buildings. Historic homes in urban neighborhoods would become more useful. Seniors could house an on-site caregiver. A family could offer a separate living space to relatives. Homeowners could earn extra rental income. With these additional options, preserving the home would seem more attractive.

Earlier this summer, the Preservation Green Lab released a report, “Older, Smaller, Better” (PDF) about encouraging urban vitality in older neighborhoods. The report contained several objectives that would be accomplished by allowing ADUs:

“Encourage compatible new construction. Infill construction that contributes to the overall physical character of a district can add vitality to a block, while also offering financial opportunities for real estate developers and investors.”

The Portland Preservation blog complimented ADUs along these lines, saying that they “are an important tool for adding density in our older neighborhoods – one home at a time. The result is far less impact on the existing character that makes our older neighborhoods so attractive to begin with.”

The City of Santa Cruz has developed a manual for ADUs with guides and prototypical designs for interested homeowners. Minneapolis could design something similar to make sure that everyone feels empowered.

The average household size in Minneapolis has decreased from 3.08 in 1950 to 2.23 in 2010. Many of the large, old homes (often built by brewing barons and milling magnates) are occupied by smaller families of more modest means today. If we’re going to preserve these homes, we have to allow homeowners to use them efficiently.

It’s clear that ADUs are part of a plan to let Minneapolis grow toward the future while respecting the past. With responsible regulations and appropriate incentives, Minneapolis can make preservation practical and even profitable.

How to support ADUs in Minneapolis

The City of Minneapolis has held two public meetings already, with two more in September. More information can also be found at:

Remaining public meeting locations and times are:


Tuesday, September 16, 2014

5:00 p.m. – 7:00 p.m.

North Regional Library

1315 Lowry Ave N



Wednesday, September 17, 2014

7:00 p.m. – 9:00 p.m.

Kenwood Community Center

2101 W Franklin Ave


This post was originally written for the Preservation Alliance of Minnesota’s blog:

Max Musicant

About Max Musicant

Max is the owner and Principal of The Musicant Group ( - a placemaking advisory firm dedicated to "Creating Great Places for People". The firm combines urban planning, design, and business management strategies to create on-going systems that improve public spaces for visitors, tenants, residents, and owners. He holds a BA from the University of Wisconsin and an MBA from the Yale School of Management