Basement finishing in Columbus

12%⁶ of homes in the city were built before 1940, and many of those basements were built for a furnace and storage, not a family room. Measure the height first. The Residential Code of Ohio generally requires habitable space to have a ceiling at least 7 feet high, but lets habitable space created in an existing basement have a ceiling of 6 feet 8 inches, with beams, ducts and other obstructions allowed down to 6 feet 4 inches.¹²

Ductwork and drain lines often hang lower than the beams, so ask the company to map what has to move before you settle on a layout.

Before converting a basement into living space, the EPA advises checking it for leaks and other signs of moisture and correcting any problems first.¹³ The EPA warns that carpet on a basement slab can stay damp from water or vapor coming up through the concrete, or from room moisture condensing on a slab that is colder than the air, and either can lead to mold.¹³

EPA's Map of Radon Zones places Franklin County, Ohio, in Zone 1, the zone with the highest potential for elevated indoor radon.³ On the EPA's radon map, Zone 1 has the highest potential, with average indoor levels that may top 4 pCi/L, Zone 2 a moderate potential of 2 to 4 pCi/L and Zone 3 a low potential under 2 pCi/L; the EPA says homes with elevated radon have been found in all three zones and all homes should be tested.¹⁴

Two houses on the same Columbus street can test very differently, so the zone tells you to test, not what you'll find. The Ohio Department of Health recommends testing every occupied ground-contact structure in Ohio for radon, and says testing is the only way to know the radon level in your home.¹⁵ 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.¹³

The EPA's guidance is to fix your home if radon tests at 4 picocuries per liter or higher, and to consider fixing it between 2 and 4.¹⁶ A mitigation system usually means a pipe through the slab and a fan, which is much easier to route before new walls and a ceiling go up. The Ohio Department of Health recommends retesting a single-family home for radon every two years, or after significant renovations that may change how air moves inside it.¹⁵ Finishing a basement can count as that kind of change, so test again once the work is done.

Inside city limits, Lead Safe Columbus can help with radon work in some older homes. Lead Safe Columbus lists average costs of $40,000 per property for lead-based paint hazard work, $4,200 for healthy-home repairs and $1,600 for radon testing and mitigation.¹⁷

In heavy rain, the public sewer in parts of Columbus can surcharge and push water back up through basement floor drains. Columbus's Project Dry Basement, which began in July 2004, covers the cost of an approved backflow prevention device for single- and two-family homes in the city that have had sewer backups from the public sewer surcharging in wet weather or from blockages.¹⁸

Columbus asks residents to report a sewer backup to its 24-hour Sewer Maintenance Operations Center and keep the service request number, which the program uses for follow-up.¹⁸ If your basement has ever backed up, ask about the program before you finish the space, since the valve belongs on the main drain under the floor you're about to cover.

The program pays for the device, not for drywall, carpet or furniture. Ask your insurer what a sewer backup endorsement would cover once the room is finished.

The Residential Code of Ohio requires every sleeping room, including one in a basement, to have at least one operable emergency escape and rescue opening, unless the home has an automatic sprinkler system and the basement has the means of egress the code spells out.¹² Under the Residential Code of Ohio, an escape opening needs a net clear opening of at least 5.7 square feet, or 5 square feet at grade floor or below grade, with a net clear height of at least 24 inches and a net clear width of at least 20 inches.¹²

In a basement with small windows up near the joists, that usually means cutting the foundation wall for a larger window and digging a well outside it. If the bedroom is meant for a tenant or a relative living on their own, read the Columbus rental conversion guide first, because a separate unit brings zoning and the new rental registry into it.

More than one in four adults 65 and older fall each year.¹⁹ Basement stairs in older Columbus houses are often steep and narrow, which makes them the riskiest part of a finished basement for a grandparent or a toddler.

A graspable rail, switches you can reach from both ends of the flight and bright, even light on the treads cost little to add during the finish. If someone will spend years living down there, 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.²⁰

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Check the company on your own before signing or paying anything. Columbus requires every contractor working in the city to hold the right city license or registration before applying for permits, and contractors in the five OCILB trades must hold the State of Ohio license first.²¹ Check an Ohio license