Artstor, the Columbia Graduate School of Architecture, Planning & Preservation (GSAPP), and the Avery Architectural & Fine Arts Library are now sharing an additional 10,000 images of architectural plans and sections and related materials in the Digital Library. 

For more information:

https://blogs.cul.columbia.edu/avery/2016/09/12/avery-gsapp-architectural-plans-sections-collection-in-artstor/