The Register of Parks and Gardens of Special Historic Interest is maintained and updated by Historic England.
Entries on the register are graded I, II* and II. They're graded independently of any buildings within them.
The designation requires local authorities to consult Historic England for development affecting grade I and II* registered parks. It also requires local authorities to consult the Gardens Trust on all grades of parks and gardens. The effect of proposed development on a registered park or garden, or its setting, is also a material consideration in the determination of planning applications.