John Bowes was the illegitimate son of the 10th Earl of Strathmore. John was always uncomfortable with living in England where, even with his wealth and status as a Member of Parliament, he felt that he wasn't accepted. In 1847, he travelled abroad and settled in Paris where he met Joséphine, an actress at the Théâtre des Variétés whom he married in 1852. Joséphine had the idea to build the Museum which was to bring the arts to the people of Barnard Castle and the North East.

The project appears to have had two purposes, one was to educate the local population and the second was to use John's wealth to build something which legitimises the couple's social position.

The building style is that of French public architecture of the time and was designed by the French Architect Jules Pellechet. We know that John Bowes used a photograph of the Tuileries in Paris for the front arched entrance, and also requested measurements of the Town Hall in Le Havre to help the design process.

The building is constructed of local Dunhouse sandstone (which was transported to the Museum on a specially constructed railway track), marble, glass and wood and is reinforced by steel joints. Each of the front doors weighs 2 tonnes each. A local architect from Newcastle (Watson) oversaw the completion of Pellechet's drawings.