Refining House (Building 19) at Former Marsh Gunpowder Works

The Refining House, also known as Building 19, is a single-storey structure built in 1789 as part of the saltpetre refinery at the former Marsh Gunpowder Works in Faversham. Constructed from yellow brick, it features a corrugated iron hipped roof and has a rectangular single-cell plan. The exterior originally had flat heads on each side, but the southeast front now includes a central vehicle entry, with a blocked doorway on the right and blocked doorways at each end.

Inside, the building has timber trusses. The Marsh works were established in 1786 as part of the Royal Gunpowder Factory to mitigate dangerous processes following an explosion in Faversham. Under William Congreve, the works significantly improved British gunpowder leading up to and during the Napoleonic Wars. The saltpetre refinery was built in 1789 to enhance the quality of gunpowder ingredients. After the war, the works were privatised and closed in the 1920s.

The Refining House was used for treating saltpetre to improve its consistency and quality and is one of the two original refinery buildings on the site. It is part of a well-preserved group of late 18th to early 19th-century industrial buildings for refining saltpetre, notable for its significance in comparison to similar examples in France and Sweden.