The state's oldest courthouse in continuous use, this imposing building is one of only two West Virginia survivors in the temple form so popular in early-nineteenth-century Virginia courthouses. Use of the Roman Tuscan order here in the 1830s, when the Greek Revival was in the ascendancy in most of the country, harks back to Virginia's Jeffersonian precedents and evidences the architectural conservatism of builder John Dunn. The central block, of brick laid in Flemish bond, is fronted by a giantorder tetrastyle portico, with plastered brick columns supporting a cornice with pediment above. A glazed lunette with radiating, spokelike muntins centers the pediment. Along with the portico, this particularly Jeffersonian feature gives the building a passing resemblance to pavilions at the University of Virginia. Although the spacing of the columns is regular, doorways and fenestration in the central bay of the three-bay facade are broader than those that flank them, and an unusual mezzanine story lies between the two main floors. An open, octagonal cupola set on a square base, capped with an ogee dome, sits at the center of the roof ridge.
Two-story wings, also of brick laid in Flemish bond, extend on both sides of the central mass. Their gable roofs sit at right angles to the main block. Originally three bays long, the slightly recessed wings were extended to their present five-bay length in 1937–1938, when a number of interior alterations were made. Further additions and modifications date from 1963.
Lot 7 of Lewisburg's original town plat, on which the courthouse stands, had long been reserved for county buildings, although the earlier log and stone courthouses were built elsewhere. Because lot 7 slopes steeply in the rear to the Lewis Spring, available building space was limited. Consequently the portico is on grade with the sidewalk on Court Street. No space was available for a flight of steps to a raised portico or for a lawn or green, customary accoutrements of Virginia's early county courthouses.
The Thomas Edgar House, diagonally across the intersection from the courthouse, was built by, and named for, the surveyor who platted Lewisburg. It is one of the earliest stone structures in town, dating from the late eighteenth century. The 20-by-16-foot dimensions of its frame wing, which may predate the stone section, accord perfectly with the 1782 town building requirements.