The Rector was Lord of the Manor and lived in a beautiful timber-framed building surrounded by a moat. The building survives, but the moat was filled in many years ago.
Built around 1450, the Old Rectory was a timber-framed hall. Since then, later owners extended the building and added sash windows. The moat was filled in sometime in the 19th century.
Across Mill Lane from the Old Rectory are the Assembly Rooms, built in the eighteenth century to help promote Welwyn as a spa and tourist destination.