Complex sentence: Built within Berkhamsted castle's former park Ashridge House is a Grade I listed building, constructed 1808--1814 to a design by James Wyatt with later work by his nephew Jeffrey Wyattville, the former seat of the Bridgewaters and later the Brownlow family.
Split into simpler sentences: Built within Berkhamsted castle's former park, Ashridge House is a Grade I listed building, constructed between 1808 and 1814 to a design by James Wyatt with later work by his nephew Jeffrey Wyattville. It is the former seat of the Bridgewaters and later the Brownlow family.