The service building of Sytin's estate is located deep within the property, along its western boundary, parallel to Sytin Lane. Together with the main house, it forms the estate courtyard. The estate also included northern and southern wings, which faced the lane with their end facades, while their elongated volumes extended deeper into the property. In the early 20th century, a four-story building was constructed on the site of the northern wing. Like the main house, the service building, known in local literature as the "carriage house," survived the Moscow fire of 1812. It was built in the early 19th century and was first shown on plans from 1803. This modest one-story structure has five axes, with a facade adorned with ribbon rustication and pierced by five large semicircular arched openings. Carriages once entered through these openings. Currently, four side openings are partially bricked up and converted into windows.

The mansard roof with five windows conceals a second floor, added relatively recently, at the end of the 20th and beginning of the 21st century. This innovation was introduced during the building's restoration after the fire, based on a project approved in 1999 by the heritage protection authorities. Although it changed the building's appearance, it cannot be said to have distorted it. The rhythm of the arches and the ribbon rustication recall the traditions of late 18th-century architecture.

After the 1917 revolution, the carriage house was converted from a service building into a residential block with communal apartments. By the end of the Soviet period, it became non-residential again, housing offices of various organizations.

Today, the restored carriage house, completed in the early 21st century, serves as an office building. It houses LLC "Gals," which carried out renovation and restoration work on the main house of Sytin's estate on a preferential program by the Moscow Government "1 ruble per 1 square meter." As a result of the restoration, completed in 2019, the main house became a laureate of the Moscow Government's competition for the best project in the field of preservation and popularization of cultural heritage sites "Moscow Restoration, 2019."