This house was built for Peter Holmes, MP, c. 1777 and probably designed by William Leeson. It was originally known as Peterfield. It was leased to Samuel Prendergast in 1823. Lewis records J.G. Prendergast as resident in 1837 and the Ordnance Survey Name Books refer to it as the residence of Counsellor Prendergast in 1840. The house valued at £49 was occupied by Thomas G. Prendergast in the mid 19th century and held from the representatives of Peter Holmes. From 1865 to 1936 Johnstown was the home of the Headech family. The house was unroofed in the early 1940s and is now demolished.