Can I buy architectural glass made from recycled glass?
No. Post-consumer glass would make a feed stock of varying compositions. This takes away control over the finished product. Architectural glass has some of the highest standards for glass that cannot be met using recycled materials.
There may be a percentage of internal(manufacturer) or pre-consumer(fabricator) cullet in your flat glass, but it is not something that is necessarily traced you could specifically request. Any cullet glass that isn’t recycled into flat glass can still be used in other applications like container glass, fiber glass or highway beads.