accessory dwelling unit rules and regulations in baltimore county

In 2025, homeowners are all about adding ADUs, or accessory dwelling units, to their properties. 

It’s an on-trend improvement that you should consider if you own a stand-alone house.

To learn more about ADU rules and regulations in Baltimore County, keep reading

guidelines for accessory dwelling units in baltimore county

An accessory dwelling unit can either be a second living quarters within a principal residence, such as an in-law suite, or it can be an accessory building situated on the same lot such as a guest house. 

It’s a space that has dedicated bathing and cooking facilities and it’s located on owner-occupied property.

Here are some of Baltimore County’s rules and regulations for ADUs:

• If you have a lot that’s 1 acre or larger, your ADU can measure up to 1200 square feet, which is approximately the size of a 2-bedroom apartment. 
• If your lot measures less than one acre (and most do) your ADU can measure up to 800 square feet, which is the size of a 1-bedroom or large studio apartment.
• ADUs must be permitted
• Construction must be done by an MHIC licensed contractor
• You cannot build an ADU in your front yard
• Rental licenses are not required if the ADU is occupied by a relative

adu information for investors

Unfortunately, Baltimore County code limits the construction of accessory dwelling units to owner-occupied properties. The code also requires that the ADU be inhabited by family members, making them a great fit for multigenerational housing.

This means that investors looking to add an ADU are without an option, which is a shame since ADUs have the ability to add affordable housing to desirable neighborhoods. 

why build an accessory dwelling unit

People build ADUs for a variety of reasons. 

ADUs can also increase the property value and offer homeowners more flexibility in how they use their space.

Homeowners can also rent out the unit to tenants, which can provide another source of income that can help offset mortgage costs or add to their regular income.

They can also serve as an additional living space for family members, provide rental income, or even function as a home office or studio. 

benefits of adus for the current housing crisis

Accessory dwelling units can be a solution to the missing middle in the current housing market.

They are also an opportunity for smart design, including green certifications. Last, they can be unexpectedly gorgeous, an infusion of contemporary design in an existing residence.

ADU’s are ideal for today’s market. 

Due to high interest rates and low inventory, for many homeowners, starter homes are becoming forever homes. 

This phenomenon has motivated homeowners to find ways to add space to their residences. It’s a wise investment.

ready to explore adding an ADU to your baltimore county residence?

At guerilla, we can assist you with reviewing all your options from feasibility to design to pricing.

Ready to build an ADU? Reach out to guerilla today.