Turning unused office space into housing could solve 2 problems, but it's tricky

1313 L St. in Washington, D.C., was formerly an office building. By the end of this year, it will be home to newly finished apartments. (Richard Morrison, Erin Kenney/NPR)

If you walked past 1313 L St. in Washington, D.C., a few years ago, you would've seen a 1980s-style office building. The headquarters for the National Association for the Education of Young Children was red brick, with big windows and the organization's logo plastered across the side.

But if you walk by the same spot this time next year, you could be looking at a newly finished apartment building with sleek gray siding and a rooftop patio.