This question was answered 2 years ago: https://www.reddit.com/r/AskHistorians/comments/1gemiw/when_were_glass_windows_first_used_and_what/

• The Romans were the first known to use glass for windows. It had poor quality and was fairly opaque around first century AD. But the ancient windows looked quite different than today's.

• Some of the earliest known examples of coloured window glass, datable to c. 800–820 AD, were recovered in excavations at the Abbey of San Vicenzo in Italy.
• The medieval glass makers used better furnaces than those existing during Roman Empire. In the 12th Century, stained glass window panes evolved to grace European cathedrals. Most of the flat glass of the 13th and 14th centuries was designed for religious ornamentation and was manufactured in France.
• Glass was very expensive and only small pieces were made at first... [because] it was laborious... blown into a balloon and then flattened. Such glass was barely translucent, full of bubbles and ripples... Lead windows used to be a necessity.
• In England, glass windows (leadlights) became common for ordinary homes only in the early 17th century.
• Across the Channel, the French had already mastered a different process for making glass couple of centuries earlier, but had kept the technology secret (and the prices high). Their process could create finer, clearer and larger pieces of glass of up to 6ft (1.8m) in diameter.
• By the 18th century, glass was getting more popular but making it involved lots of grinding and polishing. The steam engines made manufacturing a bit easier and only in the 19th century we got large panes of very good quality glass.
• By the 19th Century, store and office windows used plate glass, and the glass making centres of the world shifted to the United States [which could manufacture it more cheaply].
• Laminated glass was invented in 1903. Incorporating a thin plastic film between two sheets of glass increased the safety and security of much larger windows which could be glazed undivided by glazing bars.