Windows. Windows may perhaps use thicker glass and larger air gaps to enhance thermal insulation as well as acoustic insulation. The 4 hand-sketched graphs proven listed here under are all taken from the 1st version of a great guide called "Detailing for acoustics", created by Peter Lord and Duncan Templeton. https://acousticpodrooms62376.dgbloggers.com/30986610/little-known-facts-about-acoustic-glass