12, St Martins Lane

No. 12 St Martins Lane is a warehouse that has been converted into flats. It dates back to around 1700, with early 18th century and 19th century extensions. The building underwent partial demolition and alterations for its conversion in 1994. The original part and the early 18th century extension are made of orange-red brick in English garden wall bond, while the 19th century wing is constructed from pink and cream mottled brick in stretcher bond. The 20th century rebuild features orange-cream brick in English garden wall bond, with the ground floor of the right return finished in lined render. The roofs are covered with pantiles and have tumbled brick gables.

The building has an L-shaped plan, consisting of a main range with a wing to the left and an additional wing to the right. The exterior features a 2-storey, 3-bay front on the main range, with 2-storey gabled wings projecting forward on each side. The main range has a plain board door in the center, flanked by 2-light casement windows on both floors. The left wing has one similar window on each floor of its gable end, while the right wing has no windows in the gable end but features one window on each floor of the left return.

The left return displays a 2-storey gable wall with an attic to the left of the 2-storey wing, featuring two inserted 2-light windows on both floors and a blocked window in the gable end. The right return has a similar 2-storey gable wall with an attic to the right of the 2-storey wing. On the ground floor, there are two 2-light windows with incised arches, and on the first floor, similar windows flank a central blocked window with a shallow segmental arch of brick. There is also a similarly arched blocked window in the gable end. A rendered band of two raised brick courses runs at first floor level. All windows, unless otherwise noted, are casements with brick sills and cambered brick arches.

Inside, extensive interconnecting brick vaulted cellars run beneath the main range and the left wing. The first floor is supported by massive joists that were retained during the conversion. This building is notable as the earliest surviving structure associated with the once prosperous port of York.