Headquarters Royal School for Military Engineers and Attached Basement Area Railings, Brompton Barracks

This building is an institute, now offices, constructed between 1872 and 1874 by Sir Frederick Ommanney. It is located within Brompton Barracks, Gillingham, and was originally built as the headquarters for the School for Military Engineers, following a commission on military education in 1869. The building is constructed of yellow brick with Doulton terracotta and Portland stone dressings, featuring ashlar axial stacks and a slate roof. It is designed in the Italianate style and has a lateral H-plan with axial corridors.

The exterior is a symmetrical two-storey, attic, and basement range. The front has a plinth and modillion eaves cornice, with the end and central sections projecting forward. The ground floor exhibits banded rustication up to a moulded plat band, while the first floor has clasping rusticated pilaster strips, a frieze with enriched metopes, consoles to a modillion cornice, and a balustrade with panelled dies. Round-arched ground-floor windows have moulded heads that are linked by an impost band, and architraves and cill blocks to the segmental-arched first-floor openings. The central section features full-width steps leading to a three-bay centre with three doorways, each with keyed architraves and double half-glazed doors. The first floor is recessed behind an open loggia supported by Corinthian columns, paired to the middle with cast-iron railings of diagonal bars to a central round. Keyed architraves frame the plate-glass sash windows. The rear elevation reflects a similar articulation, with a raised roof to the central block between the parallel front and rear ranges.

The interior includes a large entrance hall divided by distyle in antis paired Ionic columns with a rear round-arched recessed arcade, impost band, and dental cornice. An axial corridor leads to an open dogleg staircase on each side, featuring ornate cast-iron balusters and a moulded rail. A central sunken library was remodelled in the mid-20th century.

Attached cast-iron basement area railings extend from the central steps to the outer corners. The building's placement on the symmetrical axis of the war memorials and the quadrangle of the Mess blocks is notable. The building is included for its historic interest, its relationship to Brompton Barracks, and as an early example of the revived use of terracotta in architecture.