There are no Metro Subway stops in Georgetown. The nearest stop is the Foggy Bottom stop on the red and blue lines. From Foggy Bottom walk north on 23rd St. to Washington Circle and bear to the left. Take a left at Pennsylvania Avenue and walk about 4 blocks to M Street. Make a left on M Street and the house will about 2 blocks on the right.
You can also catch the blue Georgetown shuttle buses at Foggy Bottom.