The following text is from the original listed building designation:
TQ 65 SE PLAXTOL OLD SOAR ROAD 4/22 (north side)
1.8.52 Old Soar Farmhouse GV II
Farmhouse. C18, on site of part of, and joined to, Old Soar to right. Red brick. Corbelled brick eaves to plain tiled roof with 3 small flat-roofed dormers. Two stone stacks to rear. Two storeys. Five window front, symmetrical glazing bar sashes with gauged flat arched heads.
Listing NGR: TQ6183653658 (1)

Listed Grade II farmhouse. Farmhouse. C18, on site of, and part of, and joined to, Old Soar to right. Red brick. Corbelled brick eaves to plain tiled roof with 3 small flat-roofed dormers. Two stone stacks to rear. Two storeys. Five window front, symmetrical glazing bar sashes with gauged flat arched heads. (1)

An archaeological watching brief was undertaken for an extension. One of the foundation trenches which ran parallel to the farmhouse exposed areas of archaeological interest. The trench exposed two areas of medieval stone walls built of large lumps of Kentish Ragstone set in a lime mortar with associated stratification. One of the areas of medieval walls running north-west, south-east was badly truncated by a cut for a modern sewer pipe, but excavation of the foundation bed of lime mortar below the pipe revealed in a secure context a single fresh, large sherd of early medieval shell-tempered pottery dated to about c.1150-1175/1200AD. No other archaeological features apart from the associated stratification to the two medieval walls were revealed during the cutting of the foundation trenches. (2)

The Kent Farmstead Survey was compiled between 1990 and 1993 and includes material from most areas around the county. Each file contains a description of the property, including historical notes, photographs and maps.
The farm buildings are described in detail.

Information also taken from the English Heritage Archives (File reference: BF096214). The main yard of buildings lie south of the farmhouse, and in the mid 19th century comprised a large courtyard of buildings apparently entered in front of the farmhouse, with access to the yard in the north west corner. There were buildings north of the farmhouse, the south wagon lodge and an oasthouse (now converted) to the north west. The Tithe apportionment shows that the farm was owned by the Hon. J W Stratford, and occupied by Charles Noakes. It was a 242 acre mixed farm with arable fields as well as hops and fruits.

Historic England archive material: (3)

Historic England, Archive material associated with Old Soar Farm, Plaxtol (Archive). SKE58534.

<1> English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.

<2> Swale and Thames Archaeological Survey Company, 2008, The results of Archaeological Monitoring & Recording at Old Soar Farm, Plaxtol, Tonbridge, Kent (Unpublished document). SKE17865.