Basement finishing in Baltimore

41%⁶ of homes in Baltimore city were built before 1940, and many of those rowhouse basements were never meant to be lived in. Headroom is the first thing to measure. The 2021 IRC requires habitable space and hallways, including the parts of a basement that contain them, to have a ceiling at least 7 feet high, and bathrooms and laundry rooms at least 6 feet 8 inches.¹¹

When a rowhouse basement comes up short, the fix is to dig the floor down and support the foundation walls below their old footings. Baltimore City lists underpinning, for homes and commercial buildings alike, among the jobs whose permit must be pulled by an MHIC-licensed contractor.⁹ Because the walls are shared, that work can affect the houses on both sides, so ask how the company handles the neighbors and whether an engineer will design it.

Robert Hooke, who rehabbed two Baltimore dollar houses in 1974 and later became a mason, says rowhouses are harder to renovate than to build new, because nothing is square and nothing is plumb.¹² Expect the framing crew to shim and scribe new walls to old brick rather than assume anything is straight.

EPA's Map of Radon Zones places Baltimore County in Zone 1, the zone with the highest potential for elevated indoor radon, and Baltimore City in Zone 2.² On EPA's radon zone map, Zone 1 counties have a predicted average indoor radon screening level above 4 pCi/L and Zone 2 counties between 2 and 4 pCi/L, and the EPA says all homes should be tested regardless of zone.¹³

A zone is a county-wide prediction, not a reading for your house. The EPA recommends testing for radon on the lowest lived-in level, so a basement that hasn't been tested should be tested before it is remodeled; fixing a radon problem is usually easier and cheaper before the basement is finished.¹⁴ The Maryland Department of Health says Maryland residents may be eligible for a free radon test kit, through the Maryland Department of the Environment.¹⁵

If the test comes back high, a mitigation system usually means a pipe and fan through the slab, and that is much easier to route before the new walls and ceiling go up. Put the result in front of every company you get a quote from.

In Baltimore City, a heavy storm can overload the sewer lines and push sewage back into basements through floor drains. Baltimore City's Expedited Reimbursement Program pays city residential customers, owners or tenants, up to $5,000 per dwelling unit per event for documented cleanup after a sewage backup caused by wet weather of at least a quarter inch of rain in 24 hours; applications are due within 90 days, and property damage isn't covered.¹⁶

That program covers cleanup, not the new drywall, flooring and furniture a finished basement would add. Before you finish one in the city, ask a plumber whether a backwater valve on the main drain makes sense, and ask your insurer what a sewer backup endorsement would cover.

The 2021 International Residential Code requires at least one operable emergency escape and rescue opening in a basement, plus one in each sleeping room, including every bedroom in a basement.¹¹ In a rowhouse, the only outside walls below grade are usually at the front and back, so an escape window often means a new areaway dug at one end of the house.

Baltimore County's alteration permit calls for construction plans when a bedroom is being created, for structural work, for second-floor additions and for additions of 600 square feet or more.¹⁰ In the city, ask the company whether the bedroom changes the plan review the permit needs. If the bedroom is meant for a tenant, read the Baltimore rental conversion guide first, because a separate apartment brings rental licensing and zoning into it.

More than one in four adults 65 and older fall each year.¹⁷ If your basement stairs are steep or narrow, as many older ones are, they become the riskiest part of a finished basement for an older parent or a small child.

Ask for a solid handrail on at least one side, a light switch at both the top and the bottom, and no throw rugs at the landing. If someone in the house will be using the space for years, ask whether the company has done aging-in-place work. NAHB's Certified Aging-in-Place Specialist (CAPS) credential trains remodelers in home modifications for aging in place.¹⁸

You call the number on this page. The call is recorded, and it goes to one independent company that handles basement finishing in the Baltimore area. You talk with them directly about water, headroom, layout and price.

We are paid for the call. You don't pay us anything, and we never call or text you. How we make money

Check the company yourself before signing or paying anything. Maryland's Home Improvement Commission licenses home improvement contractors and salespersons, and its License Search shows whether a license is current.¹⁹ Check a Maryland license