The house is bigger than it looks from the front. All together, it is about 4000 square feet
From left to right, 2 car garage, main house with 4 bedrooms and 2 full baths, then the "shop" (now rental unit) with 2 bedrooms and 2 baths.
Probably the rental unit is older than the main house, since much of the original main house burned in the 1830s. The rental unit was the carpentry and joinery shop of Hiram Waters. He apparently used it to display some of his talents since the architectural details are much fancier than those on his house.
Below is a closer look at the details of the shop. You can't see it through the storm door, but the old door is split in half. A "Dutch door" some call it, with beautiful early 19th century hardware.