The Woodchester Estate was inherited by Leigh’s son, also called William, or Willie. He was eager to complete the house but was advised that it would be more cost effective to build a new house in the park for his own family, whilst Benjamin Bucknall pointed out that the house, even completed, would need an income far greater than that enjoyed by Willie to run it. In 1878 Willie consulted Charles Hansom, who confirmed Bucknall’s estimates for both finishing the house and the cost of running it. Leigh seems to have abandoned his plans for the Mansion, instead extending “The Cottage” to fifteen bedrooms. Benjamin Bucknall moved to Algiers for the sake of his health, and died there in 1895 after finishing his career by building many attractive villas in the Moorish style.
Possibly because of Willie's habit of borrowing more than he could afford, the 1880s were a period of financial problems for the Leigh family and the estate began to suffer. The fortunes of the estate and house were improved not by his sons but through his eldest daughter, Blanche, also a devout Catholic. In 1905 she employed as agent for the estate one Ernest Poulton, who began a programme of repairs and methods of increasing revenue. Upon Willie's death in 1906 Blanche intended to complete the Mansion, and to then offer it for rent but the swift death of the heir to the estate, Frank, in 1907, put an end to the plan. The estate passed to Willie's second son, Vincent. Working with Poulton the estate flourished but when he received an offer to buy it in 1922, he sold.
Ernest Poulton was retained as the agent, continuing to work with Blanche, who managed the rents from the five farms closest to the park. This arrangement enabled her to establish a possessory title ('possessory title may be granted where an applicant has little or no documentary evidence to support their claim to the land but can demonstrate they have exercised the rights of an absolute owner for a sufficient period of time') to the central thousand acres of the estate, including the park and the mansion, which in 1935 again became the property of the Leigh family. Blanche hoped to sell the estate to a religious order but in the absence of a suitable buyer, eventually, and reluctantly (because “the beautiful Chapel will now be used for non-Catholic worship”), she sold to the Barnwood House Hospital for mental and nervous disorders. The Leigh connection was finally severed and in fact this branch of the Leigh family dies out altogether in the absence of any progeny from any of William Leigh's grandchildren.
During the second world war troops were based in the park, using the lakes to train in bridge building for the invasion of Europe after D-day. The plans made by Barnwood House Hospital did not materialise, and in 1953 they sold the property. In the 1950s Reginald Kelly took the lease of “The Cottage” and the Mansion, performing enough essential maintenance to prevent any major deterioration in its fabric. Nonetheless, in 1988 it was purchased, with twenty three acres of surrounding pasture, by Stroud District Council. The following year the Woodchester Mansion Trust was established. Private ownership of the land and the situation of the Mansion, deep in the valley, about a mile from the nearest road, have helped to protect the house from vandalism and unsuitable development, and thus incidentally preserved the magnificent building you see today.