E. M. Barry was the architect for the BMI building and it was hoped he could be retained as the architect for the adjoining library, but his plans were deemed too expensive for the Corporation. Martin & Chamberlain's plans were approved in October 1862 for a tender price of £8,600 with E. M. Barry's classical facade retained in the design. The Lending Library was opened on 6 September 1865 and the Reference Library was opened just over a year later on 26 October 1866. The chief librarian at the time of opening was John Davies Mullins. Initial use of the library was so heavy that the need for an extension was agreed in 1872 but deferred until 1878. On 11 January 1879 a fire broke out behind a wooden partition serving as a temporary wall during building operations. The fire caused extensive damage, with only 1,000 volumes saved from a stock of 50,000.