Little Cassiobury and former stable block to rear.

Little Cassiobury is a small formal late 17th century red brick mansion that served as a dower house for Cassiobury. The building is two stories high with an attic and features hipped plain tile roofs. It has three flat-topped dormers with moulded cornices and a nine-window range on the front, which includes a projecting three-window center and very narrow one-window ends. The exterior is adorned with a wood modillion cornice and a brick platband, and the windows are exposed box glazing bar sashes with gauged brick flat heads around them. The outer windows are narrow, and there is a central door with a later moulded doorcase and a pediment supported by brackets.

Inside, there is a panelled entrance hall that includes corner archways leading to the staircase and a through passage. The hall features fielded panels, a moulded cornice, and fluted pilasters on either side of the fireplace. The arches have keyblocks and moulded imposts, and the staircase wall is also panelled.

At the rear, there is a former stable block that was altered around 1930 by C Williams-Ellis. This stable block has three round-headed doorways, a pantile hipped roof, and in the center, there is an 18th century stone panel displaying the Essex arms, which was found in the grounds.