The following text is from the original listed building designation:

TR 13 SW LYMPNE
6/1 Pump House at TR 118 346
II
Pump house, disused. Early C20, by Lorimer. Small blocks of uncoursed stone with lightly vermiculated stone dressings. Concrete roof. Rectangular. 2 storeys. Slightly battered, with rounded corners and plain stone-coped parapet. Flat roof with central rectangular opening. No windows to first floor. Regular 2-window front to ground floor; openings splayed and segmental-headed, architraves wooden and slightly recessed, fixtures removed. Similar ground-floor window towards front of each side elevation. Central doorway with splayed jambs, and segmental head lower than window heads. Door removed. Similar but smaller ground-floor doorway towards rear of left side elevation. First- floor doorway towards rear of right side elevation, up 18 external stone steps set against side elevation with iron handrail. Interior: no fittings remain. Concrete ceiling to ground floor. Formerly served Lympne Castle.
Listing NGR: TR1180034600

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