Garage buildings ('Quinn's of Portaferry'), 85 High Street, Portaferry, Co Down, BT22 1QU

Garage buildings, High Street, Portaferry

Two single storey Belfast Truss roofed structures originally built as a bus depot in the 1920s, now functioning as a garage and car showroom under the name Quinn's of Portaferry. The larger building measures approximately 30 metres by 18 metres and stands on the southeast side of High Street.

The main building's northwest elevation, facing the street, is dominated by a large modern glazed car showroom window and a large flat arch vehicle entrance, with the remainder rendered plain. The northeast elevation is roughcast rendered with a large vehicle entrance with sliding door to the left and a relatively recent small single storey gabled building abutting it to the right. The southwest elevation is plain rendered with a single high-level window. The rear elevation is built in rubble stone with brick dressings to some blocked up window openings. A small single storey breeze block extension has been added to the far left, and a much larger single storey flat roofed extension to the right. The curved roof is felt-covered and incorporates two central gabled roof light projections.

To the southeast corner of the open yard behind the main building stands a smaller secondary structure, measuring approximately 18 metres by 8 metres, also with a Belfast Truss roof and now largely disused. This building is largely plain rendered with two large vehicle doorways on the northwest elevation and a large lean-to section to the southeast. Its curved roof is covered in corrugated metal with two gabled roof lights now partly covered in corrugated metal.

The Belfast truss was developed in the mid-nineteenth century to meet demand for efficient, lightweight and long span roofs driven by industrial expansion. The first known reference to a curved wooden felted roof structure supported by bowstring girders appears in a Dublin Builder advertisement for 1866 by the Belfast felt-makers McTear & Co., who continued manufacturing trusses until ceasing business in 1908. A second Belfast felt supplier, Anderson & Co., began producing trusses to a slightly different design in 1886, and in 1896 launched their Mark II version, promoted as maximising long spans whilst maintaining light weight. This model was subsequently used by other companies and is referred to by historians as the Belfast truss, though the term is widely applied to all timber bowstring trusses where the internal bracing members meet on the top curved member rather than at the bottom of the truss, as had been conventional.

Both buildings appear to date from the 1920s and are among the increasingly few large span Belfast Truss roofed buildings still in active use, though the main structure is substantially altered both internally and externally through modernisation and extension.