Numbers 6?9 (NPRNs 19371, 413636, and 423024), like numbers 20?23 at the southern end of the square (NPRN 19375), are rare examples of the original architecture of Mount Stuart Square (NPRN 400316), built in c.1858 to the design of Alexander Roos, architect to the Bute estate. The three-storey, single-bay buildings were originally built for domestic use but were later converted for commercial purposes. While the ground floors of the buildings have been altered, especially that of Perch Buildings (no 9), the second and third storeys largely retain their original character, including the distinctive second-storey Venetian windows articulated by Doric pilasters and decorated with a stucco shell in the central arch.

(Sources: Cadw Listed Buildings Database; Victorian Society Tour Notes, VS01/16)
A.N. Coward, RCAHMW, 05.07.2018