The former Welch Training School building is located west of downtown New Haven, at the northwest corner of Congress and Vernon Streets in The Hill neighborhood.

It is a 3+1⁄2-story masonry structure, built out of red brick with stone trim, and covered by a slate mansard roof.

Gabled dormers of varying styles and configurations adorn the roof faces, and a four-story gabled entry section projects at the center of the main facade.

[2] The school, completed in 1883, was designed by Leoni W. Robinson and is a good local example of Queen Anne architecture.

It was named for Harmonus Welch, the city's first president of the board of education, and later also Mayor of New Haven.