Number 5 Boathouse (Buildings Numbers 1/27 and 1/28)

Number 5 Boathouse, originally a masthouse and later a boathouse and sail loft, now serves as a museum. It was constructed in 1882 by Riley on the site of an earlier boathouse. The building is timber-framed with weatherboard cladding and corrugated iron roofs.

The structure comprises three ranges: two parallel ranges of one storey and 12 bays each, and a shorter, originally two-storey range set back against the right return. The ranges are built over Mast Pond and have small-pane wooden windows in flush wood frames, along with board doors. Bracketed eaves add detail to the exterior. The primary ranges are supported by a wood and iron substructure utilizing iron posts, wooden braces, iron girders, and wooden joists. The south-west elevation features four original wide entrances that have been replaced by twenty doors with small-pane glazing and vertical boarding. There are two louvred openings above the left-hand range, and the roofs are hipped. The range set back on the right includes a late 20th-century door within the original surround, a bracketed wooden pentice, continuous four-pane windows with a door to the left, three small-pane windows above, and two strap-hinged loading doors in the gable. The rear elevation has a diagonally-tooled stone plinth with granite kerbstones, five bays of continuous board doors or replacement vertical boarding, and a louvred gable. The left return displays a bracketed iron balcony and twelve windows. The right return includes a late 20th-century door and five windows on the right of the shorter range, and three windows on the left.

The interior features square wooden columns straight-braced to longitudinal and cross beams. The roof trusses incorporate braced wooden king posts and vertical secondary braces, as well as raking plank wind braces.

Historically, Number 5 Boathouse was one of a pair with Number 7, and represents one of the last surviving examples of a typically used building type for the construction and storage of small boats, alongside locations like the Lower Boat House, Chatham.