4 and 5, Union Passage

4 and 5 Union Passage are shops with accommodation above, built around 1806 and altered in the late 20th century. The building was likely overseen by City Architect John Palmer, but it features earlier elevations from around 1791 by Thomas Baldwin. The materials used include limestone ashlar, which is now painted, and Welsh slate roofs that are mostly hidden from view.

The building has a single depth plan and is back-to-back with Nos. 19-23 Union Street, except for No. 23. It stands three storeys tall, with an attic that is only partially visible. The exterior includes a moulded cornice, a parapet, and a mansard roof, along with a first-floor sill band. No. 4 has six windows (originally two houses), while No. 5 has two windows, all featuring glazing bar sashes with a six-over-six configuration in plain reveals. The first window from the left of No. 4 has been replaced by small paired windows with raised sills. The shopfronts were updated in the late 20th century.

Inside, there is nothing of special interest remaining on the ground floors, and the other interiors were not observed. Historically, this building was part of a city improvement scheme following the Bath Improvement Act of 1789. Union Passage is a street that has existed since the Saxon period, previously known as Cox Lane, and it appears on Smith's Map of 1588.