Significant housing developments took place during the 1920s. The architect Alexander Stewart Jolly designed a number of houses that were built in the Avalon area in that period. "Loggan Rock" was a flamboyant log cabin combined with a stone tower; the combination of logs and rocks gave rise to the name. The house is heritage-listed. "Careel House" is a bungalow made of stone that was quarried in the area. Nowadays it is on the Whale Beach side of the boundary. It is also heritage-listed. "Hy Brasil", located near Clareville, was built in 1936, but was originally known as "The Gem". Later it was bought by Ted Herman, son of the painter Sali Herman, who changed the name, using the name of a mythical island west of Ireland. It is heritage-listed. A sandstone cottage known as "Wickham", designed by Walter Burley Griffin, was unfortunately demolished with council approval in 1994.