By "long" you should be saying "height". Long and width are kind of the same thing.

There is no reason you cannot raise the lower portion of the opening by building it up. You'll have to patch in the sheetrock and the siding, and build it like the wall is built.

Don't know why they would be designed so low to the floor in small rooms unless it fits somehow with the design of the house.

Not know the type of windows you have or are planing to use my initial concern with 4' tall windows would be for egress requirements.

Pictures are very helpful in these cases.

Below is the front elevation. We are still working out the windows below as the height overall is 8 feet and we will need to bring down to 7 feet due to tray ceiling/coffered ceiling in those rooms. We are also thinking about raising these windows to avoid tempering the glass. We are making so many changes due to costs that I worry about changing the overall look of the house. At the same time, windows that will be partially hidden by furniture does not make sense to me. Thanks for the feedback!

Raising the windows looks better in my opinion.

Beautiful home. Hopefully it is on a nice piece of property.

Thanks. Do you think I should do 5 ft wide versus 6ft if I reduce height to 4 feet? Just want to make sure proportions all make sense and still look nice from exterior of home. Thanks for all the input!

Have your window supplier produce a few renderings of the windows at the sizes in question.

That will give you a good idea of the final look.

Or you can even go the the window suppliers site print the elevations and cut them out and tape them on your print elevations and look at them that way as well.