Madrid’s Contracting has spent over 35 years remodeling homes across Anne Arundel County. Starting October 1, 2026, we’re bringing that same experience to accessory dwelling unit (ADU) construction for homeowners across the entire state of Maryland.

Years in Business

Anne Arundel County Roots

& Fully Insured

Statewide Maryland Coverage Begins

An Accessory Dwelling Unit (ADU) — sometimes called a granny flat, in-law suite, or backyard cottage — is a second, self-contained living space on the same lot as your primary home. In Anne Arundel County, an ADU is capped at the lesser of 1,000 square feet or one-third of the primary home’s floor area, and it can take a few different forms:

A Converted Basement

With its own entrance, kitchen, and bathroom.

An Attached Addition

Connected directly to your main house.

A Fully Detached Structure

Built elsewhere on your property, like a backyard cottage.

Maryland passed the Accessory Dwelling Units Act of 2025, which took effect October 1, 2025. The law requires every county in the state, including Anne Arundel, to adopt a local ordinance authorizing ADU development by October 1, 2026. Anne Arundel County already has a head start — Bill 6-23 removed the county’s old minimum lot-size requirement for ADUs, meaning many more properties are already eligible than before the state law even passed.

Give aging parents or adult children their own space — steps away, not states away.

A legal, permitted ADU can generate long-term or short-term rental income.

A permitted second living unit is additional livable square footage with its own utility.

As more homeowners learn about this law, permitting offices and contractors will get busier. Start the conversation now.

Today, we’re building ADUs for homeowners throughout Anne Arundel County — Annapolis, Severna Park, Pasadena, Arnold, Crofton, Odenton, Millersville, Gambrills, Edgewater, Davidsonville, Crownsville, and the surrounding communities we’ve served for over 35 years.

Starting October 1, 2026, we’re expanding our ADU construction services statewide — bringing the same process, permitting know-how, and craftsmanship to homeowners across all of Maryland.

We evaluate your property and walk through what’s possible on your lot.

We design your ADU and handle engineering and permitting with the county.

Our team builds your ADU with the craftsmanship we’ve delivered for 35+ years.

We walk the finished space with you before you move in or welcome a tenant.

No two ADU projects are alike, and neither are their price tags. During your free consultation, we’ll walk your property and your goals so you get a clear, honest estimate — not a guessing game. A few of the biggest factors:

A 500 sq ft in-law suite and a 1,000 sq ft detached cottage carry very different budgets.

Basement conversions are typically the most cost-effective; detached structures involve new foundations, utilities, and site work.

Kitchen and bathroom finishes, flooring, and fixtures can move your budget up or down significantly.

Slope, utility access, and your specific permitting path all factor into the final number.

With decades under our belt and a plethora of successful projects, we’ve earned a reputation for dependable, quality work across Anne Arundel County.

You’ll know where your project stands at every step, from permitting to the final walkthrough.

Our commitment to excellence isn’t just a promise; it’s a guarantee, backed by top-of-the-line materials and skilled trades.

Flexible financing options make it easier to add an ADU to your property, whenever you’re ready to start.

What qualifies as an ADU in Anne Arundel County?

A second, self-contained living space on an owner-occupied, single-family lot — a converted basement, an attached addition, or a fully detached structure — capped at the lesser of 1,000 square feet or one-third of your primary home’s floor area.

Do I need a permit to build an ADU?

Yes. Every ADU requires permitting, and local zoning, lot size, and setback rules still apply. We handle the permitting process for you from start to finish.

How much does it cost to build an ADU?

Costs vary depending on whether you’re converting a basement, adding on, or building a detached structure. We’ll walk you through options and pricing during your free consultation.

Will Madrid’s Contracting build ADUs outside Anne Arundel County?

Yes — starting October 1, 2026, we’re expanding our ADU construction services to homeowners across the entire state of Maryland.

How long does the ADU process take, from consultation to move-in?

Timelines depend on the scope of the project and your local permitting office, but we keep every step moving and keep you informed along the way.

Whether you’re picturing a basement apartment, an in-law suite, or a backyard cottage, it starts with a conversation. Get in touch and we’ll schedule your free consultation — we can’t wait to work with you.

Mailing Address: 2012 Renard Court, Suite K, Annapolis, MD 21401