Even though 7 Upper Harbour is located in Reid Town, the section of Falmouth laid out by Thomas Reid in 1769, its construction date between 1815 and 1835 renders it one of the earliest surviving buildings in this part of town. The two-story structure originally had residential space on the upper floor with a storehouse on the ground floor; an exterior stair in the northwest side yard lead to the second-floor apartment, insulating the residence from the more public lower level. Unlike the storehouses on Market Street, there is no columned overhang across the front entrance to shelter shoppers. There are however, two formal street front facades, one facing Upper Harbour and one facing Jarrett Street, both with symmetrically fenestrated facades. The structure was originally stuccoed, unifying the appearance of framed and nogged west and south walls and brick north and east walls. There is only one hipped roof, compared with the tradition of multiple roofs as seen on other early Falmouth buildings such as the Baptist Manse.

The interior plan remains relatively intact. The storehouse space would have been completely open with the exception of one small room in the rear which would have functioned as an office or counting room. Three posts carry a longitudinal summer beam, only one of which might be original, although it is partially imbedded in a later partition wall. Most of the fenestration was rebuilt in the 20th century with the exception of the front doorway and rear southeast window. The front room is partitioned off now as feed store and a space where men gather to play dominos.

The upper story is also largely intact from the nineteenth century. The framing of the upper story is pit-sawn while the woodwork is sash-sawn. Some of the partition walls are frame with nogging while some are brick, and the floor is mahogany secured with cut nails. A lobby or circulation space opens into a larger public reception room covered by an elaborate tray ceiling and neoclassical cornice, while the other rooms are exposed to the rafters of the hipped roof. The lobby also opens into two chambers which were originally uncommunicating spaces, but later connected by a door around 1835-60. Additionally, there is a service or storage room in the northwest back corner, which may have been where children or servants slept.

In the mid-20th century, a kitchen space was added to the back of the rear chamber and a bathroom was added into the service room. Around 1970, the circulation space was partitioned to add another room which is now used as a bedroom. An outbuilding which functioned as a kitchen (although this may not have been its original purpose) is set behind the main structure, although only a few courses of the original brick remain and the rest was rebuilt around 1950-60.