mia1974,
I understand you want to widen some windows in your house, not lower them. Here in the NorthEast when you widen a window you have to enlarge the beam above the opening to accomadate the new size. This work is costly and reqyures a permit. Lowering windows is much cheaper as you can work under the existing beam.
Widening a brick opening is the most costly. You see not only do you have to open theinterior wall to build a new opening with the proper size new beam but you'll also have to hire a mason to to carefully remove the bricks ablve the existing window and more to remove the angle iron holding up the brick and then replace it with a longer one.
Additionally the left and right sides of the brick opening would have to either be vertically cut by a professional or hand broken out and and re-bricked by a mason. If you can leave one side intact and expand the window in just one direction, you;ll save the money for the side cut.
We enlarge windows all the time. Wood openings are the easiest. Your project tops the list in cost.
Masonry with both cuts (one left & right)and a longer iron angle to hold up the brick would cost 2,000. The interior carpentry to open the interior wall and put a new longer beam in place, install the new window and build a new jamb and wood work it would be another 2,000.
Now add the cost of the new window, the wood, the beam and the finishing, spackling, etc.

Unfortunately widening is costly.

Any questions, get in touch.

All the best,

The Porch Guy

Here is a link that might be useful: My Album

Hi Can you please tell me how much it cost to widen a window in one direction (left/right)?
Also from what you have explained I gather that it doesn't cost much to increase the length of the window downwards??
I need rough estimates please

Can you let me know if the price is the same or less if you are enlarging it by lowering it only, and keeping the width the same? My dining room was originally a sitting room in the 70's with a window kinda high up, like a bedroom window. I want to drop it to give it a "picture-window" effect. Thank you!

By "lowering" it only I would assume that you mean you are lengthening the window height? If so, yes that changes the window pricing for certain.

+1. If you are not changing the width of the head height, only extending down to make larger, that is the least costly way to make a window larger as it requires the least amount of work. No need to re-header the opening... This will still be a substantial added expense over a standard installation, but a bit less than expanding in other directions

That's a lot of work and it will be very expensive either way. Just be prepared

Hi Anglophillia , is it possible for you to email me the old and new picture of the windows at my e ID - neetu_aayush@yahoo.co.in

I am a first time home owner and am struggling with small windows in my living room.. want to get them enlarged but have no idea of the cost and final outcome...Would really appreciate your guidance and tips.

thanks .