Can I Build An ADU?

Montgomery County · Premier ADU Builder

Montgomery
County, MD
ADU Rules

Learn the official ADU rules, size limits, parking requirements, and licensing steps so you can build with confidence.

A small blue house with white trim sits in a sunny, fenced backyard surrounded by green trees and plants. There are two windows and a glass door facing the yard, with a neighboring house visible in the background.

What is an ADU in Montgomery County?

An Accessory Dwelling Unit (ADU) is a second residential unit on the same lot as a single-family home. It must include facilities for cooking, eating, sanitation, and sleeping and remain subordinate to the main home.

Montgomery County ADU Size Limits

10%

of the total lot size

50%

of the main house footprint

1,200

square feet of floor area

Have Questions?

Talk with Makara ADU, your local Montgomery County, MD ADU expert, about your property.

ADU Requirements in Montgomery County

How many ADUs are allowed

One ADU per residential lot

The ADU must share the same street address as the primary residence

Parking Requirements

Within 1 mile of Metro, MARC, or Purple line station: no additional parking required

Outside transit area: typically 1 additional parking space required

How many ADUs are allowed

Class 3 Accessory Dwelling Unit License required from the county

Must be licensed before renting

Required even if the unit is not rented

Must comply with housing, zoning and landlord-tenant laws

Montgomery County ADU Approval Process

1

Check Zoning & Lot Eligibility

2

Design Your ADU

3

Apply for Building Permit

4

Apply for Class 3 ADU License

5

Pass Inspection & Get Approval

What Homeowners Build ADUs

Income

In as little as 120 days from permit, you can start earning rental income from your Makara ADU that can change your life.

Lifestyle

Makara Builders Accessory Dwelling Units provide much needed additional space to accommodate all of your needs, or the needs of your loved ones.

Community

Nestled beautifully into your backyard, our ADUs provide a much needed solution to the housing needs of the area without impact to the immediate community.

Choose a Makara ADU Plan

Choose and customize one of our amazing designs, or design your own for your Montgomery County ADU!

Choose A Plan

Choose and customize one of our amazing designs, or design your own.

Frequently Asked Questions

Yes. Once your ADU has passed final inspection and you have obtained a Class 3 Accessory Dwelling Unit License from Montgomery County, you may rent the unit. Owner-occupancy of either the ADU or the primary residence is required.

The maximum ADU size is the smallest of: 1,200 sq ft of floor area, 10% of the total lot size, or 50% of the primary home footprint. For most Montgomery County lots, 1,200 sq ft is the hard cap.

Yes. A building permit from Montgomery County DPS is required, along with a Class 3 ADU License from DHCA before you can legally occupy or rent the unit. Makara handles both filings on your behalf.

Can I Put an ADU on My Property?

In a matter of minutes we can determine if you can put a Makara Accessory Dwelling Unit on your property.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Floor plan of a studio ADU featuring a living/kitchen area, a sleeping area with a bed, bathroom, and washer/dryer. The open layout is ideal for tiny home living, with furniture and appliances clearly marked.

MAKARA 300

STUDIO

300 Sqft

Studio apartment floor plan perfect for a Tiny Home or Accessory Dwelling Unit: combined living, kitchen, and dining space; Murphy bed, sofa, table, and kitchenette along one wall; bathroom and washer/dryer in the corner. Room measures 18-7 by 12-4.

MAKARA 375

1 Bedroom

375 Sqft

Floor plan of a small ADU with living/kitchen area, bathroom, washer/dryer, shelves, walk-in closet, and sleeping area. Furniture includes a sofa, table, bed, and kitchen appliances—ideal as an Accessory Dwelling Unit or In-Law Suite.

MAKARA 380

1 Bedroom

380 Sqft

Floor plan of a small apartment or ADU with an open living and dining area, kitchen along one wall, bathroom with a bathtub, and a separate bedroom with a double bed. Ideal for an ADU builder or garage conversion project.

MAKARA 450

1 Bedroom

450 Sqft

Floor plan of a two-bedroom apartment ideal as a Garage Conversion or In-Law Suite, featuring a central living/kitchen area, bathroom, washer/dryer, and bench. The master bedroom is on the left; bedroom #2 is on the right with kitchen appliances along the upper wall.

MAKARA 480

2 Bedroom

480 Sqft

Floor plan of a two-bedroom apartment ideal as a Garage Conversion or In-Law Suite, featuring a central living/kitchen area, bathroom, washer/dryer, and bench. The master bedroom is on the left; bedroom #2 is on the right with kitchen appliances along the upper wall.

MAKARA 480

Garage

480 Sqft

Floor plan of a one-bedroom ADU featuring a bedroom, bathroom, closet, open living/dining area with kitchen, workspace, and deck. Furniture and fixtures are arranged throughout this modern tiny home.

MAKARA 640

1 Bedroom

640 Sqft

Floor plan of a one-bedroom Accessory Dwelling Unit (ADU) featuring a bedroom, closet, bathroom, kitchen with island seating, dining area, living room with sofa and chairs, and a small porch at the entrance. Perfect as an in-law suite.

MAKARA 660

1 Bedroom

660 Sqft

One-bedroom accessory dwelling unit floor plan with bedroom, bathroom, closet, kitchen, and open living area featuring sofa, chairs, and dining table. Light wood flooring and marble accents throughout.

Makara 800

1 Bedroom

800 Sqft

Floor plan of an ADU with two bedrooms and one bathroom on the left, a central kitchen and dining area, and a spacious living room with seating on the right. A closet and entry door are also shown.

Makara 900

2 Bedroom

900 Sqft

2-bedroom apartment floor plan: ideal as an Accessory Dwelling Unit or garage conversion. Each bedroom has a bathroom and closet. Central kitchen with island, dining, and living area. Patio at the bottom; storage and laundry rooms near the top.

Makara 1100

3 Bedroom

1100 Sqft