The mission house in Middle Swan which had been built for the Revd (???) Giustaniani was built on a narrow strip of land which was known as the "Mission Grant" was purchased for £150. The 866 acre (350 ha) grant was originally given to settler John Wade in September 1829. It ran for about 10 miles (16 km) from the river to the Darling Range but was only 10 chains (220 yards/200 m) wide. The house was made of mud bricks with a thatched roof and is believed to have stood where Huddelston House now stands at Swanleigh, a short distance from St Mary's.