The following text is from the original listed building designation:
FAVERSHAM
TR 06 SW HAM ROAD
659/6/10019 Earth House (Building 5) at former Mar
14-DEC-01 sh Gunpowder Works, Workshop Area
GV II
Earth house at saltpetre refinery, part of gunpowder works, now workshop and store. 1800-10. Yellow brick with corrugated hipped roof.
PLAN: Rectangular single-cell plan with central dividing wall.
EXTERIOR: Single storey, formerly with nine openings to each side with rubbed brick flat heads, mostly blocked or altered on the SW side. NE side has original 8/8-pane hornless sashes, two flanking a doorway in the E end, two more closely-spaced wither side of a near-central doorway, and two taller windows to the E end flanking another doorway. Inserted vehicle entrance to NW end.
INTERIOR: Five king post trusses with pairs of ties to end walls and diagonal struts, corner ties, the roof lined with matchboard.
HISTORY: The Marsh works were part of the Royal Gunpowder Factory which was established outside Faversham in 1786 after an explosion in the town, to remove some of the more dangerous processes. They played an important part in the improvement of the British gunpowder leading up to and during the Napoleonic Wars, under William Congreve. The saltpetre refinery was built in 1789 as part of Congreve's successful drive to improve the ingredients of British powder. It was privatised after the war, and closed in the 1920s.
Earth houses stored unrefined saltpetre, imported from the East Indies, previous to treatment in the refinery complex (qv), and this is the earliest and last surviving of six which were built here in the early C19. The relatively elaborate fenestration suggests that it may have also have been intended for or very soon adapted to other purposes. This building forms part of a discrete, coherent group of late C18 - early C19 industrial buildings for refining saltpetre, the best preserved of this type in the country and comparable with French and Swedish examples.
(Wayne Cocroft, Dangerous Energy. The archaeology of gunpowder and military explosives manufacture. Swindon (English Heritage), 2000, pp. 54-67).

In 2019 an historic building recording of the former Marsh Gunpowder Works buildings now situated within the former Oare Mineral Works, Faversham, Kent was completed in advance of works to the designated and non- designated heritage assets. (2)

English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.

<2> Headland Archaeology (UK) Ltd, 2019, Historic Building Recording of the Marsh Gunpowder Works within the Former Oare Mineral Works, Faversham, Kent (Unpublished document). SKE54278.