Built in 1915 to the design of Teather & Wilson, Baltic House is an Edwardian Baroque-style, yellow-brick building of six storeys and 5+1 bays. The building occupies much of the the southern side of Mount Stuart Square (NPRN 400316), facing the Coal Exchange to the north (NPRN 31766).

The main fascade of the building is of five bays with an arcade of channel rusticated round aches in the lower-ground and ground floors. The entrance is in the central arch, in a red-granite architrave bearing the name `BALTIC HOUSE? with a tripartite light above. The other arches have windows. There are cartouches decorated with nautical motifs in the spandrels. The third fourth and fifth storeys have tripartite sash windows separated by three-storey ionic pilasters. There are exaggerated keystones above the third-storey windows. Above the fourth-storey windows are oval-shaped garlands surrounding nautical figures. A dentilated cornice supports iron railings above. The eastern-most bay is markedly different from the rest of the building, with a channel rusticated facade and a three-storey canted oriel window in the third, fourth, and fifth storeys above which is an arched window with exaggerated keystone. The asymmetrical construction of the building may indicate that it was not completed to the original plan, although the building to the west, number 20 Mount Stuart Square (NPRN 19374), substantially predates Baltic House, being one of the few surviving examples of the original architecture of the square.

From the late 1980s the building was the headquarters of the Cardiff Bay Development Corporation. It is currently (2018) the headquarters of the Wales Council for Voluntary Action.

(Sources: Cadw Listed Buildings Database; Victorian Society Tour Notes, NMR MS VS01/16; Newman, Buildings of Wales: Glamorgan (London: 1995), p. 271)
A.N. Coward, RCAHMW, 05.06.2018