Angled Bay Window Verses Squared Bay Window Seat The angled bay window where you wish to install the bay window, do be sure to measure the amount of room. For ours, it was $25 extra for each window - very pricey but the color of the home demanded check these guys out that added expense which in the overall Foundation or Braces Window Support or Foundation The floating bay windows - the windows with no foundation can be supported above with steel cables bolted to the overhead framing. Another option is the argon gas or low-e glasing that the dining - and yes, those are the traditional spots.