National Westminster Bank and Attached Walls

The National Westminster Bank, built in 1876 by GM Silley for the National Provincial Bank, is a bank located on the High Street in Chippenham. It is constructed of limestone ashlar and features a hipped slate roof with moulded ashlar stacks that rise from the eaves. The building is designed in a Mannerist Classical style and has a double-depth plan with rear extensions.

The exterior is two storeys high with a symmetrical five-bay front. It has wide eaves, a dentilled cornice, and a blocking course on the facade and returns. The first floor is adorned with horned plate-glass sash windows, and the central three bays are recessed and articulated by fluted Doric columns in antis, flanked by carved floral drops. Paired antae are present on both outer bays, with curved brackets supporting the cornice above. The ground floor and side walls feature chamfered rustication below an ornamental band, along with a triglyph frieze at sill level. The flanking ranges of the entrance are recessed, with a moulded impost band and semicircular-arched windows that have heavy moulded keystones set in an ornamented band. The glazing is from the 20th century. The building has a moulded sill and plinth, with steps leading up to a 20th-century door that is flanked by Doric columns resting on the plinth and supporting the impost string. Above the door is an ornamented semicircular panel that continues the arcading of the windows. The returns of the building are similar but simpler in design.

On each side of the bank, there are coped walls that rise to meet the triglyph frieze. Each wall features a wide flat arch with chamfered voussoirs and a large keystone; the arch on the right includes 20th-century double gates. This bank is a vigorous and eclectic example of Palazzo-style mid-19th century commercial architecture, contrasting with the more conservative style of the adjacent No. 29.