21 Frogmore Street

Nos. 21 and 22 Frogmore Street are late 17th century townhouses built of red brick, with some areas featuring roughcast render and applied timber framing. They have a natural slate roof and a red brick chimney stack. The buildings are set on a narrow medieval burgage plot and feature a gable end facing the street. Each house is three storeys tall, with a wide bay for each premises and a narrow bay in between, which is part of No. 21 and possibly part of No. 22 at the rear.

The ground floor has shopfronts with a central entrance; the shopfront of No. 22 appears to be less altered than that of No. 21. There is a narrow central bay with a through passageway. On the first floor, No. 21 has red brick while No. 22 is painted. Both have canted oriel windows with paired 1 over 1 pane sashes at the front and narrow similar windows on the flanks. These windows feature pedimented heads that are incorporated into the gables above. There is a central window over the passageway, which is a 1 over 1 pane sash with an elliptical head.

The second floor has large timber framed gables for both premises, with roughcast between the timber. Each gable is supported by console brackets carved with lion's heads. There are two windows in each gable; No. 21 has fancy Edwardian sashes with a multi-pane over 2 configuration, while No. 22 has plain 1 over 1 pane replacements. The apex of the gable features tile hanging, with plain bargeboards and a spike finial. The central bay has a cornice between the floors and a triple window with small 6 over 1 pane sashes. The roof is plain with a central ridge stack.

No. 21 retains its unpainted brickwork and original windows, although the shopfront has been altered. The rear elevation has not been inspected. The interior was not seen during the resurvey, but the ground floor has few visible historic features.