How does Maryland compare with the national average for an accessory dwelling unit (ADU)?

Homeowners in Maryland typically recoup about 46% of the project's cost at resale, versus ~41% nationally. Maryland is part of the South Atlantic Census division, which has the 3rd-highest renovation resale returns of the 9 U.S. divisions.

What most affects the actual return in Maryland?

Recency and condition. In Roots' model, work under 2 years old counts fully toward resale value, then depreciates toward ~20% after 10 years. A home with a documented maintenance record also typically sells closer to asking. Market conditions in the South Atlantic division set the regional baseline.

Where do these numbers come from?

Roots calibrates the national baseline for an accessory dwelling unit (ADU) against the 2025 Cost vs. Value Report (Zonda), then applies a South Atlantic-division adjustment derived from division-level averages in the 2024 Cost vs. Value Report, plus the model's own age and condition factors. Figures are modeled estimates, not appraisals.

Is an accessory dwelling unit (ADU) worth it in Maryland?

Quick answer: It can be. In Maryland, an accessory dwelling unit (ADU) typically returns about 46% of its cost at resale, above the ~41% national average. You likely won't recoup the full cost, but Maryland is one of the stronger markets for it.

How Maryland compares

Maryland is part of the South Atlantic U.S. Census division, which has the 3rd-highest renovation resale returns of the 9 divisions in Roots' valuation model. In practice that means an accessory dwelling unit (ADU) that returns ~41% of its cost nationally typically returns ~46% for a Maryland home.

The same regional adjustment applies across the division (Maryland plus DC, DE, FL, GA, NC, SC, VA, WV). Nationwide, the spread for this project runs from ~34% in the West North Central division to ~48% in the Pacific division. See the national breakdown for every region.

The South Atlantic market

The South Atlantic, running from the D.C. suburbs down through the Carolinas, Georgia, and Florida, has been one of the country's strongest in-migration corridors, and steady buyer demand pushes renovation returns above the national average. The housing stock skews newer than the Northeast, so buyers often expect modern layouts and finishes as the baseline.

Fast-growing metros in this corridor absorb added living space readily. Extra room tends to find a willing buyer.

How other projects return in Maryland

Project	Typical return in Maryland
Accessory dwelling unit (ADU) (this page)	~46%
Wood deck addition	~92%
Bathroom remodel	~82%
Basement remodel	~79%
Window replacement	~74%

Return figures are typical resale-return estimates from Roots' home valuation model. Actual results vary by market, home, and workmanship, and shouldn't be relied on for lending, insurance, or tax decisions.

Sources: national baseline for this project calibrated against the 2025 Cost vs. Value Report (Zonda); regional adjustment derived from division-level averages in the 2024 Cost vs. Value Report.

Protect the value you add

Whatever the project returns on paper, condition decides what you actually get: in Roots' model the value of completed work fades as it ages, and a documented maintenance record helps a home sell closer to asking. If you're planning around resale value, start with upkeep. The free maintenance checklist generator builds a seasonal schedule for Maryland homes in about a minute.

The bottom line

“According to Roots' home valuation model, Maryland's South Atlantic region has the 3rd-highest renovation resale returns of the 9 U.S. Census divisions. An accessory dwelling unit (ADU) there typically recoups about 46% of its cost, within a nationwide range of ~34% to ~48%.” — Roots home valuation model (regionally adjusted resale-return estimates)

Free tool Keep your home in the condition that holds its value The homes that hold their value are the ones that stay well maintained. Build a free maintenance checklist tuned to your home. It takes about 30 seconds and there is no signup.

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Frequently asked questions

Is an accessory dwelling unit (ADU) worth it in Maryland?: It can be. In Maryland, an accessory dwelling unit (ADU) typically returns about 46% of its cost at resale, above the ~41% national average. You likely won’t recoup the full cost, but Maryland is one of the stronger markets for it.
How does Maryland compare with the national average for an accessory dwelling unit (ADU)?: Homeowners in Maryland typically recoup about 46% of the project’s cost at resale, versus ~41% nationally. Maryland is part of the South Atlantic Census division, which has the 3rd-highest renovation resale returns of the 9 U.S. divisions.
What most affects the actual return in Maryland?: Recency and condition. In Roots’ model, work under 2 years old counts fully toward resale value, then depreciates toward ~20% after 10 years. A home with a documented maintenance record also typically sells closer to asking. Market conditions in the South Atlantic division set the regional baseline.
Where do these numbers come from?: Roots calibrates the national baseline for an accessory dwelling unit (ADU) against the 2025 Cost vs. Value Report (Zonda), then applies a South Atlantic-division adjustment derived from division-level averages in the 2024 Cost vs. Value Report, plus the model’s own age and condition factors. Figures are modeled estimates, not appraisals.

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