1 Sion Terrace, Sion Mills, Co Tyrone, BT82 9HB

An end-of-terrace two-bay two-storey house built around 1860, located on the east side of Church Square in Sion Mills. The building is rectangular on plan with a one-and-a-half-storey gabled return to the west, further abutted by a single-storey flat-roofed extension. A lower two-storey annex was added to the north-west around 1995.

The roof is pitched natural slate with terracotta ridge tiles over corbelled eaves. Chimneys are smooth rendered with clay pots; the return features a yellow brick corbelled chimney. Single rooflight to the east pitch; two rooflights to the west. The walls are painted roughcast over a smooth banded plinth, with the return smooth rendered. Windows are replacement square-headed uPVC casements in smooth reveals with painted masonry sills. Cast-iron half-round gutters and round downpipes serve the roof.

The principal elevation faces east. At left is a round-arched-headed opening with stepped painted brick surround containing a recessed four-panelled timber entrance door with etched glazed top panels and transom light. A single window occupies the ground floor right, with two windows at first-floor level. The south gable is abutted by an adjoining listed building. The west elevation is abutted at right by the gabled return; the exposed section at left contains single windows to each floor. The north elevation of the gable contains a single window to the first floor and a timber entrance door at ground floor, with blank west and south elevations. The north gable is blank, with evidence of a now-demolished single-storey attached structure at ground floor. The house is directly accessed from the street at east. A roughcast boundary wall with concrete coping encloses a yard to the rear, accessed through a square-headed vertically-sheeted timber door. A garden across a path to the rear is bounded on all sides by timber fencing.

The building was constructed as workers' housing by Herdman & Co, a flax spinning mill that established Sion Mills as a company-owned model village. The terrace first appears on the third edition Ordnance Survey Map of 1905, though Annual Revisions to the Valuation records show No. 4 from 1880, No. 5 from 1897, and Nos. 6 and 7 from 1898, suggesting Nos. 1-3 are somewhat earlier. The houses are recorded in contemporary documents as "house, offices and small garden" leased from J&E Herdman, valued at £6 10s (Nos. 1-4), £7 rising to £15 by 1898 (No. 5), and £8 10s (Nos. 6-7). According to historical records, the village was originally built with simple one-storey terraced cottages. In the early twentieth century, under Captain Ricardo as Director of personnel and welfare, second storeys were added to many houses as the linen boom of 1903 increased demand for workers, enabling residents to take in lodgers during the week. The Herdman family operated the village on lines similar to Robert Owen's New Lanark, providing comprehensive worker support including a shop, dispensary, doctor and nurse funded by worker contributions, fire service, and trained maintenance staff. In the early 1960s, facing capital needs during a linen industry downturn, the company privatised the village by selling houses at prices ranging from £60 for the smallest to £120 for two-storey houses.

Despite modernisation in recent years including replacement of windows and doors, the terrace retains many original features including yellow brick chimneys, gabled returns, and largely intact interior layouts. The group remains architecturally important within Sion Mills and benefits from its setting overlooking Church Square.