The early 20th century saw development in Orpington begin in earnest. Francis Austin was a surveyor who, by 1910, had begun to build houses on the east side of the main railway line.

Beginning with Hill View, adjacent to his offices he spread north beginning the huge Knoll development, Perry Hall, Scads Hill and Carnwell Wood, the latter now considered part of the later Petts Wood developments.

Little is known of Austin and it seems likely that the first World War prevented him fulfilling his aims as presented on this map.

After the war Aubrey Mullock, who had established an estate agency in the High Street became the main force behind Orpington's development. The exact location of this board is unknown but a site close to the station and Austin's estate office seems likely.