56 Commonwealth Avenue was designed by architect George Nelson Jacobs and built in 1930 as a five story, 22-family apartment house. It was built for Frederick E. Johnston, who is shown as the owner on the original building permit application, dated February 10, 1930. The Charlestown Five Cent Savings Bank is shown as the owner on the 1938 Bromley map.

By 1974, 56 Commonwealth was owned by 56 and 60 Commonwealth Associates, which also owned 60 Commonwealth. In September of 1974, they converted 56 Commonwealth into 28 condominiums and 60 Commonwealth into eight condominiums. When it was built in 1930, 56 Commonwealth replaced a townhouse that had been designed by Snell and Gregerson, architects, and built ca. 1866. It had been one of four contiguous homes (54-56-58-60 Commonwealth) built at the same time in a Georgian Revival style, with bow fronts and balustraded parapets above the main cornice.

The original house was built as the home of Mrs. Maria (Francoeur) Sayles, the widow of Willard Sayles, a textile manufacturer and merchant. At the same time, her son, banker and broker Henry Sayles, had 58 Commonwealth built next door, and her her son-in-law and daughter, Dr. John Cauldwell Sharp and Helen Sharp, had their home built next door, on the other side, at 54 Commonwealth. Henry Sayles lived only briefly at 58 Commonwealth, if at all, and by 1870 was living with his mother at 56 Commonwealth. He was unmarried.