[1] The asylum was designed by Kendall & Pope in the High Victorian Gothic style to a corridor plan layout.

[1] The foundation stone was laid on in October 1851 and the hospital was officially opened as the Essex County Lunatic Asylum in September 1853.

[4] Brentwood Hall, which had been declared unsafe, was rebuilt and reassigned as an occupational therapy department.

[4] After the introduction of Care in the Community in the early 1980s, the hospital went into a period of decline and eventually closed in 2001.

[1] A medium secure unit known as Mascalls Park Hospital remained on the site until 2011.