17-29 Mill Street, Comber, Co. Down, BT23 5EG

Terrace of seven houses and shops on the north side of Mill Street, Comber, comprising two distinct groups of differing age and character.

The eastern group (Nos. 17–21) consists of three two-and-a-half-storey houses dating from approximately 1870–80, built in Scrabo sandstone with brick dressings. No. 17 has a panelled front door with a plain fanlight, flanked by painted stone pilasters beneath a plain blocking course and projecting stone cornice. To the right of the door is a top-hung PVC window with astragals giving a sash-like appearance, set within brick dressings and plain rendered reveals. The first floor has two evenly spaced windows of the same type but slightly shorter. At second-floor level, two gabled half-dormers contain windows of similar design but with semicircular heads; these dormers are fitted with decorative pierced bargeboards and timber finials. The short sections of roof between the dormers each drain to a separate rainwater pipe. Nos. 19 and 21 are largely identical to No. 17, except that No. 19 has a modern half-glazed timber door, and No. 21 has a half-glazed door and a shallower cornice to the door case. The ground floor front facade of No. 21 is finished in greywacke field stone rather than sandstone, which suggests it may have been constructed around a much older single-storey structure; it is also notably shallower in plan than Nos. 17 and 19.

To the rear of No. 17 is a single-storey lean-to kitchen extension to the right, with a large multi-pane PVC window to its north face and a back door to its east side. To the left on the main rear facade are two modern windows, one at ground floor and one directly above at first floor, with a small high-level window to the upper right. The rear of No. 19 is almost identical. The main rear facade of No. 21 is slightly recessed, with a two-storey gabled return to the right and a single-storey lean-to extension to the left of it. A single modern window sits to the upper left of the main rear facade, and a similar window appears to the left of centre of the two-storey return. The ground floor of No. 21 is obscured by plant growth and outbuildings. The east gable of this group is blank. The west gable rises above its neighbour, is rendered, and is also blank. The gabled roof over this eastern section is covered in asbestos-free slate, with four brick chimney stacks and a Velux window to the rear on each property. Rainwater goods are a mixture of cast iron and PVC.

The western group (Nos. 23–29) consists of four two-storey properties of probable pre-1834 origin, built in greywacke rubble construction. Their vernacular character has been significantly compromised by the insertion of modern shopfronts.

No. 23 has a large full-width modern aluminium shopfront and door inserted at ground floor level. An externally illuminated sign with large metallic-looking letters reading "Comber Pet Stores" runs across the front. The first floor has two sash-like top-hung PVC windows with both vertical and horizontal astragals. To the rear is a large two-storey flat-roofed return finished in plain render. Its north face has a door to the ground floor right and a modern window to the first floor centre; the east and west faces are blank. An open lean-to roof spans from the rear wall to outbuildings used as stores.

No. 25 is largely in original condition. The front has a timber-sheeted door with a simple painted stone surround to the right, and a sash window without astragals to the left. The first floor has two similar sash windows. To the rear left is a small single-storey lean-to return with a corrugated asbestos roof, a modern window to its north face, and a sheeted timber door to its west face. A window opening to the right of this return is now blocked. At first floor level is a sash window to the right of centre.

No. 27 has a modern aluminium shopfront at ground floor with a glazed door to the left side and a large internally illuminated plastic signboard above. The first floor has one sash window, left of centre, matching those of No. 25. To the rear right is a single-storey brick-built gabled extension, with one squarish timber fixed-pane window at first-floor level to the right of the ridge of the return roof.

No. 29 has a large new multi-pane shop window with a wide rendered surround and apron to the right side of the ground floor, and a modern glazed door to the left with a simple painted door surround surmounted by a simple cornice. The first floor has two sash-like PVC windows with cement render bands. The rear facade has recently been finished in smooth render. At ground floor left is a deeply recessed multi-pane door. At first floor are a small PVC window to the left (serving a bathroom), a larger one immediately to its right, and a tall PVC window to the far right lighting the landing. To the rear of No. 29 is a two-storey outbuilding, the ground floor of which is used as a store and the first floor of which has been recently upgraded for use as an office. The east gable of this outbuilding is finished in random rubble greywacke stone and shows evidence of a former single-storey building having been removed from the site. The gabled roof of this western section is covered in asbestos slates to the front and a mixture of asbestos and Bangor Blue slates to the rear. There are two recently rebuilt chimney stacks to the centre of the roof, above No. 25. Rainwater goods throughout this section are PVC.

The site is shown as occupied on a 1722 map of Comber and on all subsequent maps available. The 1834 valuation records describe this part of Mill Street as containing "houses exempt" — that is, properties falling below the rateable value threshold — and the four western properties (Nos. 23–29) may well be among these, given their greywacke construction and vernacular appearance, suggesting an 18th-century origin. The three eastern properties (Nos. 17–21) are considerably later, dating from approximately 1870–80, although No. 21 may incorporate an earlier single-storey dwelling within its fabric. Nos. 23 and 27 had already been converted to shops by the time of the first survey in December 1975.

Historical sources consulted include the 1722 Survey of Comber from the Londonderry Papers (PRONI D.654/M1B/2), maps of Mill Street dating from 1793 to 1828 (PRONI D.654/M54), the first valuation of 1834 (PRONI VAL 1B/316A), Ordnance Survey maps of 1834, 1858, and 1901, and the second valuation of 1861. The researchers note that the 1834 and 1838 valuation records for Mill Street and Castle Street are particularly difficult to interpret due to a revaluation carried out in 1838, which involved annotations to the original record book, the apparent discarding of the original valuation map, and the production of a new map with a different numbering system. As a result, correlating standing buildings with the 1834 records is, in many cases, difficult and in some cases impossible.