The properties along Ida Avenue in Mosman stand 10 m above the road on an
outcrop of Sydney sandstone. Access to the houses is generally via a long steep
staircase. The owner of 22 Ida Avenue identified an opportunity to use the
natural strength of the rock beneath his property to excavate an underground
garage and to provide access to the basement of his property via a 10 m elevator
shaft from the back of the garage.
This paper will describe the design and construction of this unique and
innovative urban development.