35+ Years Building in Anne Arundel County
Add Space, Add Income, Add Home — Built by Local Experts
The ADU Builder is the accessory-dwelling-unit division of Madrid’s Contracting — 35 years of Anne Arundel County construction experience, now focused on detached, attached, and conversion ADUs.
What Is an ADU, and Is It Legal in Anne Arundel County?
An accessory dwelling unit (ADU) — also known as an in-law suite, granny flat, or carriage house — is a smaller, independent living space built on the same lot as a single-family home. ADUs have their own entrance, kitchen, and bathroom, and can be detached, attached, or converted from existing spaces such as a garage, attic, or basement.
Yes, ADUs are legal in Anne Arundel County. The County Council passed its own ADU ordinance in 2023 — years ahead of Maryland’s statewide ADU law — giving local homeowners a clear, established path to build. As the ADU division of Madrid’s Contracting, we’ve been helping Anne Arundel County homeowners build compliant, quality ADUs since that ordinance passed.
How It Works
Three Steps From Idea to Move-In
Free Consultation
We walk your property and talk through goals, budget, and zoning — no cost, no obligation.
Design & Permitting
Our team draws the plans and handles Anne Arundel County permitting from start to finish.
Build & Move In
Our own crews build it — the same team that's built Anne Arundel homes for 35 years.
ADU Types
Find the Right ADU for Your Property
Detached ADU
A detached ADU is a fully separate backyard structure — the most popular accessory dwelling unit in Anne Arundel County for homeowners who want maximum privacy and long-term rental flexibility. Anne Arundel’s 2023 ADU ordinance allows detached units on nearly every residential lot, with no minimum lot size required.
Fastest Turnaround
Garage Conversion
A garage conversion ADU is the fastest, lowest-cost path to a livable accessory dwelling unit in Anne Arundel County — no new foundation, no site excavation, and often a lighter permitting lift than a detached build. We handle the full county permit process for garage-to-ADU conversions from start to finish.
Fastest Turnaround
Attic Conversion
An attic conversion ADU makes use of space you already have, turning unfinished upper-floor square footage into a fully permitted accessory dwelling unit. Anne Arundel County still requires proper egress windows and structural review for attic ADUs, which our team manages as part of your permitting package.
Fastest Turnaround
Basement Conversion
A basement conversion ADU is often the lightest permitting lift of any accessory dwelling unit type in Anne Arundel County, since the structure and foundation already exist. Egress windows are still required by code, and our team handles that compliance work as part of every basement ADU conversion.
Local Expertise & Trust
The ADU Builder is the accessory dwelling unit division of Madrid’s Contracting — 35 years of licensed, insured remodeling and construction across Anne Arundel County, Maryland. Same crews, same accountability, new focus: helping local homeowners navigate Anne Arundel’s ADU ordinance and build detached, attached, and conversion ADUs the right way, the first time.
Transparent Pricing
No lowball teaser quotes. Every Anne Arundel County ADU project starts with a free, on-site consultation where we walk your property, review your zoning district, and give you a real number — in writing — before any work begins. Most ADU projects in our area run $120K–$300K+ depending on type, size, and finishes.
Full-Service Permitting
Anne Arundel County has required ADU permits since its 2023 ordinance passed — well ahead of Maryland’s statewide ADU law. We handle Anne Arundel County (and Annapolis city, where applicable) permitting from drawings to final inspection, including zoning verification, plan review, and code compliance, so you don’t deal with the county at all.
Transparent Pricing
Most ADU Projects Run $120K – $300K+
Exact cost depends on ADU type, size, and finishes — we give you a real number after a free on-site consultation, not a lowball estimate.
Why Build an ADU
Reasons to Build an ADU
Rental Income
Turn unused yard or garage space into steady monthly income.
Aging Parents
Keep family close with a private, accessible space of their own.
Guests & Family
A comfortable place for visitors without giving up your main home.
Adult Children
Give grown kids independence while staying close to home.
Service Areas
Serving Anne Arundel County
- Severna Park
- Annapolis
- Crofton
- Pasadena
- Glen Burnie
- Arnold
FAQ
Anne Arundel County ADU Questions
The ADU Builder is a licensed Anne Arundel County ADU builder serving Severna Park, Annapolis, Crofton, Pasadena, Glen Burnie, Arnold, and surrounding Maryland communities. As the accessory dwelling unit division of Madrid’s Contracting, we bring 35+ years of local construction experience to every detached ADU, attached ADU, and garage, attic, or basement conversion we build.
Ready to Add Space to Your Property?
Get a free, no-obligation ADU estimate from Anne Arundel County’s trusted local builder.