Rosemont, owned in 1887 by Mrs Ann Tweddell, is significant to Cardinia Shire as an example of the rural retreats built in shire resort areas during that decade. It is significant for its association with the Tweddells, well known district Methodists.
This is a simple and typical late 19th century weatherboarded hipped roof return-verandahed house with a projecting gabled bay with bracketed eaves, architraves to windows, and fringed and moulded barges. Simple iron brackets adorn the verandah and corrugated iron covers the roof. The main door has side and top-lights. Mature Monterey cypress are at the front and side of the house.