The existing building is dated to about 1600 as an L-plan tower house and underwent it alterations in the 19th century with the addition of a Baronial-style wing in 1895.

The buyer was Highland Estates Ltd.[6] In 1946 the Erchless Estate and castle were bought on behalf of Baron Siegfried Nikolai von Stackelberg, an anti-communist refugee member of the Baltic German nobility and his wife Baroness Phyllis von Stackelberg.

The Estate continued in the ownership of the Trustees of George Roscoe until 1963–64, but the Valuation Roll for the following year names the new Lairdship of Erchless (estate) as being held by the family of Sir Lawrence Robson, founder of accountancy firm Robson Rhodes.

[7][8] However, the Trustees did not sell the whole of the former Erchless Estate: the Valuation Roll for Kilmorack for 1964–65 records them as still owning Teanassie House, and most of Breakachy.

Their gravestone reads: "In memory of Baron Nicholas Stackelberg of Teanassie House, much loved husband of Phyllis, died 30 September 1966.