How Much Does it Cost to Build an ADU?
Learn what it costs to build a garage apartment ADU (Accessory Dwelling Unit) in Minneapolis or St. Paul, and what drives those costs.
South Minneapolis ADU
Building a Garage Apartment in South Minneapolis
Follow along as we build an Accessory Dwelling Unit (ADU) above a new garage in South Minneapolis.
Current Step
Footings & Foundation
Footings & Foundation
We’re laying the foundation, and making way for utilities, so we can start to build the new garage and ADU.
Footings
The new garage and ADU will be supported by frost footings. The footings guard against settling and slippage that can damage the new structure. They also keep posts and beams from direct contact with the earth. Going below the frost line helps prevent soil movement due to frost called “frost heave”.
Pouring the footings. Per code, footings in Minneapolis must be between 54 and 60 inches deep.
Footings continue across the garage to support the weight of the building.
Laying the CMU (also known as block).
Backfill
Clean fill is brought in for backfill and to prep for the new slab. The sand compresses and compacts easily and tightly to create a good solid surface to build on. We’re replacing the excavated soil because it contains roots and stones that might prevent it from compacting, which could create voids and sinkholes, leading to foundation damage. Sand helps the new garage concrete slab and driveway in a couple of ways. First, it creates a good drainage plane over our sub-soil/existing soil, and it also aids in working the concrete slab to get a nice level surface. The soil removed at excavation is taken away and repurposed or used in re-grading the yard as needed.
Want to learn more about
this type of project?
We’re here to help! Check out our planning resources below, or reach out to us here.
Creative Ways to Make Space: Accessory Dwelling Units
Interested in an apartment above your garage, a backyard studio, or a workshop detached from your house? ADUs are fully functional living spaces that can have many uses.
Think you can’t afford that remodel? (There are more options than you think.)
So you’d love to upgrade your kitchen or add a shed dormer with a primary suite, but you’re not sure how to pay for it? Learn about three ways to finance your remodel.
