What does "backyard cottage" mean?
A backyard cottage is a friendly name for a detached ADU. It is a small, complete second home that sits behind your main house. It has its own front door and its own bath and kitchen space, all on your lot.
Maryland state law calls it an accessory dwelling unit. Since October 1, 2025, it has been a by-right use in charter counties like Charles. "By right" means the county judges your application against its written rules, not by opinion. A complete zoning application gets a yes or no within 90 days, with no discretionary hearing.
If you want the builder's view of what a detached ADU involves, start with our detached ADU builders guide. This page is about the cottage itself: the charm, the design, and who it fits.
Sources: Chapter 197 of the 2025 Laws of Maryland (HB 1466/SB 891), §§4-501, 4-505.
Cottage styles that suit Maryland lots
A cottage earns its name by looking like it belongs. We match your roofline, siding, and colors so the new building reads as family, not an add-on. Farmhouse porches, gabled roofs, and craftsman trim all fit Charles County streets.
Here is a quiet bonus from the state law: the county may not reject your design for "neighborhood compatibility" or looks. Only objective, measurable rules count — size, setbacks, height. Taste is not a permit criterion.
Sources: Chapter 197 of the 2025 Laws of Maryland (HB 1466/SB 891), §4-504(C)(5).
Who is a backyard cottage for?
Aging parents who want independence nearby. Adult children starting out. Long-term rental income. A home office with a door that closes. Guest space for the holidays. One lot, one cottage, many chapters of life.
Want the compact end of the range? See small ADUs. Want it drawn from scratch for a tricky lot? See custom ADUs. We build across Charles County and Southern Maryland.
How big can your cottage be?
Charles County's published draft rules (not yet confirmed as final law) set the caps. On lots under 3 acres: 1,000 square feet or 75% of your main home's floor area, whichever is smaller. On lots of 3 acres or more: 75% of the main home's floor area, with no absolute cap. No more than 2 bedrooms, and never more bedrooms than the main house has. One ADU per lot. Height is capped at 2 stories or 24 feet.
Placement rules for detached cottages on lots under 3 acres: meet the zone's front setback, sit at least 6 feet behind your home's front building line, keep at least 6 feet to the side and rear lot lines, keep at least 6 feet from other buildings, and never build inside a recorded easement (an easement is a strip of your lot reserved for utilities or access). On lots of 3 acres or more, the cottage can go anywhere but must stay at least 50 feet from a public road right-of-way.
Sources: Charles County Bill 2026-06 / ZTA 25-189 (published draft), §§3.01.700.E, F, G, H.
What does a backyard cottage cost?
Makara ADU, a Maryland ADU builder quoted in The Banner, puts the cost to build an ADU at $150K–$350K. That is their published figure, not our quote — your lot decides your number.
A note on prices: material costs move up and down, and no two lots need the same work. Treat any numbers on this page as starting points, not quotes. Your written estimate after our free lot walk is the real number for your project.
Sources: Makara ADU (quoted in The Banner).
Your HOA gets a vote too
Maryland law says your HOA can't unreasonably limit your ADU — nothing that drives the cost way up or blocks the project in practice. But the HOA still has teeth: it can ban short-term rentals of the ADU, and it can treat the ADU as a separate lot for dues and voting. The county's own staff position is "HOA guidelines apply" — the county won't overrule your neighborhood's private covenants. Read your CC&Rs before you pay for plans, and get the HOA's architectural approval in writing early. Sources: Real Property §2-126 (Chapter 197 of the 2025 Laws of Maryland); Charles County staff briefing to the Board of County Commissioners, April 28, 2026.
Check it yourself — or skip the homework
Don't take our word for any of this. Zoning and permit questions: Charles County Planning & Growth Management, 301-645-0692. Well and septic questions: Health Department, Division of Environmental Health, 301-609-6751. The county's published draft rules are Bill 2026-06 / ZTA 25-189 ("Flexibility for Accessory Dwelling Units"); the state law is Chapter 197 of the 2025 Laws of Maryland (HB 1466/SB 891).
Or skip the homework: call (240) 222-5082 and we'll walk your lot free and tell you what your county allows — before you spend a dollar.