The following text is from the original listed building designation:
TQ 7570 SE FRINDSBURY EXTRA HIGH STREET, Upton
(North side)
Description from record TQ 77 SE 1305:
Used to protect magazine complex ie housing troops and later police.
Owner : Public
Publicly accessible : Yes
How accessed for survey : Open to public (English Heritage / Medway Council).
Tourism Potential : Already tourist attraction.
Condition : good
Date of visit : 07/07/15

Description from record TQ 77 SE 37:
High Street, North Side, Upnor. The Barracks. Barrack block, now store. 1717-18 in the Vanbrughian Ordnance Baroque Style. Red brick in English bond. Plain tiled roof. Double depth plan with twin span roof. [Full architectural description] LISTED GRADE II*. (1)

1797/15/52
The Barracks, Upnor Castle
14.11.1986
GV I
Barracks, now store and museum. 1717-18, for the Board of Ordnance. Red English bond brick with ridge and gable stacks, and tiled valley roof Double-depth plan, divided into 3 separate sections by spine and central rear transverse walls.
EXTERIOR: 3 storeys and attic; 5-window range. Symmetrical front has a plinth, rusticated brick quoins to a second floor cornice, attic with wooden eaves cornice, parapet and paired, coped gables. Flat-roofed porch with cornice and parapet, steps up to round-arched doorways each side, a small segmental-arched window in the front, and a segmental-arched doorway with panelled double doors; segmental-arched 6/6-pane sashes and smaller second-floor windows, the outer ones paired with a lead downpipe and dated hopper between. Left-hand double basement doors in the plinth. Cornices extend to returns with paired gables, 2 attic sashes to the front gable and 2 oculi to the rear, each with a doorway to the rear. The rear left-hand gable has a weather vane.
INTERIOR: entrance lobby to a dogleg stair with uncut string and plain rail to a first-floor landing with trap door; the rear sections each have dogleg stairs up from the side entrances; collar truss roof with through purlins. Cast-iron C19 fireplaces, and wooden clothes racks in former bedrooms.
HISTORY: accommodated the garrison for Upnor Castle (qv), from 1668 one of the largest powder stores in the country. In the early C19 it housed 2 officers in the front section, and 64 soldiers in the rear. One of the first purpose-built barracks in England, in the style associated with Hawksmoor and the Ordnance Board at this time, and part of a Erne group with the Castle.
(English Heritage Handbook: Saunders A D: Upnor Castle, Kent: London: 1985-: 15).
Listing NGR: TQ7581070504 (2)

Additional reference (3-5)

<1> DOE(HHR)City of Rochester upon Medway, Kent. 14 (14.11.86) (OS Card Reference). SKE41289.

<2> English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.

<3> David Evans, 01/01/06, Arming the Fleet (Article in monograph). SKE14473.

<4> MMRG, 07/07/07, Upnor Castle Barracks (Photograph). SKE14536.

<5> Peter Kendall, 2006, Historic barracks in Medway (Unpublished document). SKE15939.