On 18 July 1244, William sanctioned the foundation of Crossraguel Abbey in Carrick, after Donnchadh, Earl of Carrick had given donations to Paisley Abbey for this purpose, but Paisley Abbey had merely founded a chapel and kept the balance. Bishop William's episcopate saw continued work on the cathedral and significant expansion in the resources of the diocese.
In 1244, William sanctioned the foundation of Crossraguel Abbey in Carrick after Donnchadh, Earl of Carrick had given donations to Paisley Abbey for this purpose, but Paisley Abbey only established a chapel and retained the remainder. Bishop William's episcopate witnessed continued work on the cathedral and an increase in the diocese's resources.