The central main entrance has a tall eight-panel door in a plain frame with a stone surround.
The hipped roof is of old tiles, and has three dormer windows, and the house has square brick chimneys with stone quoins.
Garth's wife Rebecca Brompton was the granddaughter of Sir Richard Raynsford, Chief Justice of the King's Bench.
Their son, another Wadham Locke (1779–1833), later a Member of Parliament, was born in the house in October 1779 and married the heiress Anna Maria Powell in Salisbury in 1802.
From 1901 until about 1929 or later the house was occupied by the two unmarried daughters of Henry S. Hilman, a barrister of Kent, Worcestershire, and Kensington, who had died in 1893.
Architectural plans for 'alterations and additions' to Brownston House by the architect Harold Brakspear drawn up in December 1901 are preserved in the Wiltshire and Swindon Archives.
When no longer required for this purpose, it fell into disrepair and was bought by Kennet District Council, which undertook a programme of restoration and repair.