Maryland · Prince George's & Montgomery Counties · ADUs & Accessory Dwellings
Maryland Homes with ADUs and In-Law Suites for Sale
Multigenerational living. Income offset. Aging parents. House hacks. The reasons buyers want an ADU vary, but the search criteria don't get any easier. "ADU" isn't a search field on Zillow. It's buried in remarks fields, ambiguously labeled as "two-unit," "in-law suite," "detached cottage," or sometimes nothing at all. We built this page to surface what's actually available.
What counts as an ADU in Maryland
An Accessory Dwelling Unit is a complete, smaller living space on the same lot as a primary residence — with its own kitchen, bathroom, and sleeping area. Legal definitions and permitted configurations vary by jurisdiction. Here's the summary for the counties where we work:
| County | ADU Status | Key Notes |
|---|---|---|
| Prince George's | Attached, internal, and detached permitted on most single-family lots | Size and parking requirements apply. Our primary focus market. |
| Montgomery | Attached ADUs by right; detached ADUs with conditional approval in many R-60 and R-90 zones | Takoma Park and Chevy Chase have strong existing ADU stock. |
| Howard | Attached ADUs (accessory apartments) under specific conditions | Verify lot and zoning before purchase. |
| Baltimore | Permitted in specific zoning districts | Check most recent zoning regulations. |
| Anne Arundel | Permitted with a use permit in many residential zones | Verify with county planning before offer. |
If you're considering adding an ADU to a home you're buying, the answer to "can I do that?" depends on the lot, the zoning, the setbacks, and sometimes the HOA. We help buyers vet this before they go to contract.
Why ADU-eligible homes are worth a closer look
Multigenerational Families
House aging parents or adult children with privacy on both sides. One lot, two households, no shared front door.
House Hackers
Rental income from $1,200–$2,200/month offsets a meaningful share of the mortgage at current rates. Maryland's ADU rules make this more achievable than ever.
Investors
Underwrite the ADU as a separate rental stream. Most listings still price these as single-family homes — the rental income is unpriced upside.
Maryland's ADU rules have loosened significantly over the past five years, and Prince George's County and Montgomery County have been especially active. The market hasn't fully caught up yet — meaning ADU-ready properties are often still priced like single-family homes, with the ADU upside as a hidden option.
Where ADUs work best in Maryland
The strongest fit is older streetcar suburbs with deep lots and detached garages — many of which can be converted to ADUs more cheaply than a ground-up build. Hyattsville, Mount Rainier, Riverdale Park, Brentwood, College Park, and Takoma Park all have stock that fits this profile — quarter-acre lots, existing detached structures, and zoning that increasingly supports conversion.
What we look for
When we're searching for clients, we filter for:
- Lot size large enough to permit a detached ADU under local zoning
- Existing structures — garages, carriage houses, basements — that can be converted at lower cost than new construction
- Proper egress and ceiling height in basements for legal conversion
- Separate utility metering potential
- Off-street parking that satisfies ADU parking requirements
Right for you if
You want a home that can generate income, house family, or both — and you're willing to do the diligence to find one that's actually zoning-eligible. The best ADU opportunities don't describe themselves as such. You need an agent who knows what to look for in the lot dimensions and property history, not just the listing description.
Wrong for you if
You're assuming any home with a finished basement is ADU-eligible — it may not be. Or you're projecting rental income before verifying that the unit can be legally rented. The gap between "has a nice basement" and "has a permitted, rentable ADU" is significant, and conflating the two is the most common expensive mistake in this category.
Related reading
- What a Scary Foundation Report Really Means in the DMV Relevant if you're converting an older basement — foundation conditions affect feasibility and cost before you break ground.
- Priced Out of Takoma Park? Here Are Four Neighborhoods Worth a Serious Look. Three of the four neighborhoods covered are strong ADU markets — with the price data to show why the math works there.
For Route 1 Corridor ADU opportunities specifically, the Route 1 Corridor overview is the place to start — Hyattsville, Mount Rainier, and Riverdale Park are our strongest ADU markets.
Current Listings — Updated Daily From Bright MLS
Maryland homes with ADUs, in-law suites, detached cottages, and accessory dwelling potential — Prince George's and Montgomery Counties.
What buyers ask about Maryland ADUs
What is an ADU and how does it differ from an in-law suite?
An Accessory Dwelling Unit is a complete, smaller living space on the same lot as a primary residence, with its own kitchen, bathroom, and sleeping area — fully self-contained. "In-law suite" is informal language that often means the same thing, though it sometimes implies an attached configuration or a space that's connected to the main house rather than fully separate. The legal distinction matters for permitting, rental eligibility, and financing.
Which Maryland counties allow ADUs?
Prince George's, Montgomery, Howard, Baltimore, and Anne Arundel counties all permit ADUs under varying conditions. Rules differ on attached versus detached configurations, size limits, parking requirements, and rental use restrictions. Local zoning is the controlling factor — always verify before purchase. Our primary focus is Prince George's and Montgomery Counties, where we know the rules best and where the ADU-ready housing stock is strongest.
Can I build an ADU on a home I'm buying?
Sometimes yes, sometimes no — it depends on the lot size, zoning district, required setbacks, and any HOA restrictions. Many older streetcar-suburb lots in Hyattsville, Mount Rainier, and Riverdale Park are well-suited for detached ADU conversion of existing garages or carriage houses. We help clients vet this specifically during the due diligence period so they don't buy a home expecting an ADU that the lot or zoning won't permit.
Is buying a home with an existing ADU a good investment?
Often yes, because most listings in the Route 1 Corridor still price ADU-equipped homes as single-family properties without fully capturing the rental income potential. A finished, permitted basement unit or detached cottage renting for $1,200–$2,200/month offsets a meaningful share of a mortgage at current rates. The ADU functions as a hidden value driver — priced in by sophisticated buyers, overlooked by everyone else.
Which Maryland neighborhoods are best for ADU conversion?
Older streetcar suburbs with deep lots and existing detached garages tend to convert most cost-effectively. Hyattsville, Mount Rainier, Riverdale Park, Brentwood, College Park, and Takoma Park all fit this profile — quarter-acre lots, existing detached structures, and zoning that increasingly supports conversion. These neighborhoods also have strong rental demand given their DC-proximate location and Metro access.
All information deemed reliable but not guaranteed. All properties are subject to prior sale, change or withdrawal. Listing information is provided for consumers' personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Market statistics sourced from Movoto and Zillow Home Value Index, April 2026; ADU premium and rental ranges reflect market-observed data and are not guaranteed; refreshed quarterly. Zoning information is general in nature and subject to change — verify current regulations with the relevant county planning department before purchase. Equal Housing Opportunity.