In 1862, the castle was put up for sale by the Strathmores and purchased by William Briggs, a local timber merchant and ship builder. Briggs set about to change the appearance of the castle to what he believed to be more "authentic medieval". He demolished the north and south wings, gutted the interior and added one, two and three-light cusp-headed windows. He also replaced the Gothic porch with a more "severe" Gothic doorway (three-bayed with cinquefoil arches) and an overhead balcony. To carry out these changes to the west front, he moved the stone-carved Hylton banner from above the west entrance to the front, left-flanking tower. The interior walls of the four-vaulted ground floor rooms were demolished, the whole floor was raised three-and-a-half feet and two reception rooms were formed. At the east end of the former central passage, dog-leg stairs were constructed leading to the first floor, requiring removal of the oratory and rendering the main staircase inaccessible from the ground floor. The side walls of the great hall were removed to create a large salon and a large bay window was added to the south façade, where the entrance to the south wing would have been. The rooms above were kept untouched, except that a new entrance to the family/chaplain's room had to be formed via the main staircase.