Built of grey fieldstone, Horla church is unusual for having never had a window cut into its north wall, a feature it shares with only three neighbouring churches. Before the 18th century, north-facing windows were rare in general, since that side of a building was traditionally associated with darkness. In 1684 fire, which spread from nearby buildings, destroyed the church so thoroughly that only the walls remained standing; the roof was subsequently rebuilt and the walls repaired.
The outward appearance has changed little since then. A timber porch was added in the 18th century, and in 1845 a further window was cut into the south wall while the two existing windows were widened. The roof covering has changed materials several times over the centuries, moving between shingle, tile and oak shingle, most recently to plain clay tile.
Inside, Horla is notable for retaining its narrow Romanesque chancel arch, decorated with medieval ashlar-imitation painting, a feature few churches in the region have preserved. The furnishings are well preserved throughout, and the gallery is placed, unusually, on the north side of the nave — a reminder that small medieval churches often had to make use of every available space to accommodate their congregations.
The pulpit dates from around 1690, and in 1715 its body was painted, and its sounding board carved, by the Borås sculptor Gustaf Kihlman, who also produced the altarpiece that same year. South of the church stands a free-standing wooden bell tower, built in 1697 by the master builder Jon of Säckegärde and clad in timber in 1721. The large bell is of a late medieval standard type and bears no inscription. The current organ was built in 1966 by A. Magnusson Orgelbyggeri of Gothenburg.