Completed in 1781, it was intended to be a summer house for the governors, but remained in constant use until the present structure was finished in 1831.

The original plan as conceived by Governor Cochrane was for a Palladian style two-storey house, plus basement.

When completed in 1831, Government House cost £38,175, which was five times the original estimate; equal to £3491958.09 today.

The two-storey building consists of a centre block flanked by slightly lower wings on the east and on the west.

The exterior is of rough, red sandstone quarried at Signal Hill, trimmed with English Portland stone.