The Real Estate Associates (TREA), founded and incorporated by William Hollis in 1866, was one of the first companies to mass produce detached housing for families of varying income levels.

During the decade of the 1870's, TREA built more than one thousand Italianate houses based on designs in pattern books. TREA crews built a typical house in sixty days. The most expensive homes cost $6,000 or more, and the more affordable homes were in the range of $2,500 to $4,000. The buyer made a down payment between twenty and fifty percent and had from one to twelve years to amortize the loan at an interest rate of eight to ten percent.

TREA was dissolved in 1881, a victim of the depression which had lingered since 1877 and, perhaps, of its own business practices.

A number of beautifully maintained TREA Victorians also stand in the Bush Street-Cottage Row Historic District in Pacific Heights.