Plas Bach is a good example of an estate farmhouse built c1870-5 as part of the general rebuilding of the farms on the island by the 3rd Baron Newborough. Of the 11 new houses, 8 were semi-detached, 3 detached including Plas Bach, Carreg Fawr and the chapel house. Plas Bach is said to have been the superior house intended for the factor or visiting owner, with superior interior fittings and the only pumped well.