Detached ADU
Services · Detached ADUs

Detached ADU Builder in Madison.

Detached ADUs are fully independent structures built on your existing property. Separate entrance, separate utilities, maximum privacy — and the highest return on investment of any ADU type.

What Is a Detached ADU?

Your Property.
A Second Home On It.

A detached ADU is a standalone structure — fully separate from your main home — built on the same lot. It has its own foundation, its own entrance, and its own systems. From the outside, it looks like a small house. From a zoning perspective, it's permitted as an accessory dwelling unit.

In Madison and across Dane County, detached ADUs are permitted on most single-family and two-family residential lots — subject to minimum lot size, setbacks, and height requirements. We confirm all of this during your feasibility check.

Check My Property →
Detached ADU exterior
Who Builds Them

The Right ADU for Your Situation

Detached ADUs serve a range of needs. The common thread: homeowners who want maximum flexibility and long-term property value. Common versions: an in-law suite, a backyard cottage, or an accessible ADU.

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Rental Income
A detached ADU is a permanent rental on land you already own. Long-term or short-term, the separate entrance and private yard are what tenants pay for — and the equity stays with the property.
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Aging Parent or Adult Child
Close proximity without shared walls. A single-level home starting at $145K keeps an aging parent thirty steps away instead of a $12,000–$15,000-a-month care facility — about one year of those fees, and the outlay stays in the property. The B-436 is the plan we use for that.
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Guest House + Future Rental
Use it now as a guest suite or home office. The same structure can serve as a rental unit when your needs change — flexibility is built into the asset.
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Property Value
A permitted, built-to-code detached ADU adds documented square footage and an income-producing unit to your property. It's one of the strongest value-adds available to residential property owners.
Typical Project Details

What to Expect

Size range300 – 1,000 sq ft (lot-dependent)
Project timeline4–6 months, not including extended permit review
Typical price rangeStarting at $145K
FoundationFull perimeter, frost-depth compliant
UtilitiesSeparate metering available
HVACMini-split system, standard
Wisconsin energy codeFully compliant

Size and price vary by lot, municipality, and design. Your feasibility check establishes what's possible on your specific property.

Our Process

How We Get There

01
Feasibility + Design Brief
We confirm your property can support an ADU and define the project scope, size, and budget range.
02
Architectural Design
Floor plan, elevations, and material selections — designed for your lot and your goals.
03
Permitting
We prepare and submit all permit applications. You don't deal with the municipality — we do.
04
Construction
Site work through final finishes. We manage the build and keep you updated throughout.
05
Certificate of Occupancy
Final inspection, CO issuance, and project handoff. Your ADU is ready to use.
Standard Inclusions

Turnkey Construction. Zero Napkin Math.

Design, permitting, and residential finishes are in the number. Appliance packages are available. They are not assumed in the base price.

Design + Architectural Plans
Full Permitting
Mini-Split HVAC
Appliance Packages Available
Quartz Countertops
Luxury Vinyl Flooring
Slow-Close Cabinetry
Lifetime Composition Roof
Dusk exterior of a Boundless ADU with warm light in the windows, Madison WI
Ready to Find Out What's Possible?

Start with a Free Feasibility Check

We'll review your address, zoning, and lot — and tell you whether a detached ADU is buildable, how large it can be, and what it'll take to get there.

Get Your Free Feasibility Check →