Because you are almost certainly going to be increasing the width of the opening and very likely raising and lengthening the support header over the window as well you are going to to be above the cost in the referenced comments probably in the 2000.
Cost of converting windows to french doors.
Here is a recent response on cost to install a sliding glass door which is quite a bit easier than a french door but same general size.
So you ve just built a new deck on the back of your house and those once lovely double windows in the living room would now make a better door sliding glass or french out to that awesome deck.
The door you will be replacing the window with will be about two inches narrower than the window.
Sysysysref tue 13 jun 17 15 40 13.
There s also another option you might not have considered yet converting an existing window into a french glass door.
This means that a 32 window will not convert to a 32 door but rather a 30 one.
You can expect an average cost of 525 and up.
It doesn t need a support or lintel it just needs the window removing and the brickwork underneath the window removing.
This might be enough for some people but it is worth considering whether the door will be wide enough.
Cost to convert a window to french doors 8 posts add message report.