The following information comes from Trysor report no. 2018/640, which was produced during a Level 1 building recording undertaken by Trysor in November 2018.
'This building was originally a barn which was associated with a house which stood just to the northwest during the 19th century. Neither building appears to have existed at the time of the Ordnance Survey Original Surveyors Drawings were surveyed in 1813, but both are shown on the Llanwenarth parish tithe map of 1843. The tithe apportionment for Llanwenarth parish (dating to 1842) records the property as an unnamed "house and garden" on the holding of Pentre Farm. The house and barn are both shown as being in use on the 1901 1:2500 scale Ordnance Survey map. The 1960 1:2500 scale map shows that the house had been abandoned and by the end of the 20th century it had been demolished. The barn was converted into a dwelling at some point during the 20th century and it is that cottage which is known as Little Pentre in modern times.'
Source: Trysor report entitled 'Level 1 building recording for proposed two storey extension to exsisting dwelling at Little Pentre, Twyn Allwys Road, Govilon, NP7 9RT planning application 18/16325/ful (BBNPA)' by Jenny Hall and Paul Sambrook, November 2018
M. Ryder, RCAHMW, 27th February 2019