Basement fires can be deadly, and homeowners who want to add a bedroom to a below-grade space need to consider whether they will need to carve out at least an emergency egress window as part of their renovation. While the code historically has called for two means of escape on all floors, it has evolved in response to deaths because of fires in basements and attics, said Eric Mays, Prince William County Building Development Division chief. The highest risk of death in a fire is when people are asleep, so the regulations emphasize sleeping quarters in those spaces.

The code changed as building inspectors caught on to ways some homeowners avoided the requirements, said Dave Merrick, owner and president of Merrick Design and Build in Kensington. “People applied for a permit for an office or gym and used it as a bedroom.”