This is the oldest surviving building on the Canterbury Plains and was built by Scottish brothers John and William Deans, assisted by their fellow settlers. The Deans arrived in Canterbury in 1843, having first tried to settle in Nelson [and Wellington]. They became, along with their farmworkers, the Gebbie and Manson families, the first Pakeha to settle permanently on the Canterbury Plains. (A small group, led by James Herriot, had attempted to settle at Putaringamotu in 1840 but this had failed and the small settlement was abandoned by 1841.)

The first house to be built for the Deans was a three-roomed cottage with an overhead loft. The central room was used by the Deans, and the two end rooms by the Gebbie and Manson families. By September of 1843 William could describe, in a letter to his father, the house, cowshed, stable and calf house which they completed. This first house survived until 1890 and its site is today marked by a plaque and an oak tree planted by Jane Dean, John's wife.

This cottage, their second, was also built in 1843, out of local totara, matai and kahikatea taken from the adjacent bush. The fireplace and chimney were made from cob and the roof was shingled. In 1856 the Deans family moved from the cottage to Riccarton House (also registered by the New Zealand Historic Places Trust Pouhere Taonga.)

In 1950 the cottage was moved 170 metres upstream to a site near the current Scout Den and restored by the Rotarians. In 1970 it was moved again to its present position near Riccarton House. It is now owned by the Riccarton Bush Board of Trustees and is open to the public. Also associated with the house is the adjoining remnant of native bush, gifted to Christchurch City by the Deans family in 1914. Riccarton Bush is the only surviving stand of the wetlands podocarp forest in Christchurch, and is dominated by kahikatea.

Deans Cottage is significant as the sole survivor of the group of buildings erected by William and James Deans between 1843 and 1845. It is the oldest extant Pakeha house on the Canterbury Plains and is associated with one of Canterbury's prominent families. In conjunction with Riccarton Bush and Riccarton House it demonstrates the history of the area: from the bush that existed prior to Pakeha settlement through to the initial cottages of the settlers and the later houses built by the successful immigrants.