The house passed out of the Henderson family in 1799, and was inherited by Elizabeth Nicolson and her husband Thomas Mouat of Garth, the builder of Belmont House on Unst. Their nephew, William Mouat, added the porch and constructed the steading and Gothic cottage in the grounds. Sir Walter Scott dined at Gardie House during his 1814 visit to Shetland. In 1905 the house was altered, and remains privately owned. In 2001, the owner was John Hamilton Scott, Lord Lieutenant of Shetland.
