looking to buy new windows. Hears my plan. I want to tear out the drywall return and the window stool before they measure for my new windows. I'm assuming that beneath that is probably a 1 by lumber frame that the window was manufactured with. Any reason why I should not remove the drywall? Ive been told that when companies install replacement double hung windows they measure the opening with the drywall returns and mount the window in that frame. I want this because after new windows are installed i want to build my own jamb extensions. Also I feel pretty confident that I could install the windows myself but couldnt do the flashing on the outside. I think it's called capping? Are there poeple that will do this and if so what do you think the rate per window is?

 

How thick is the wall that is housing the windows? If it is a typical 4 9/16" then you probably have metal windows? If you have traditional double hung then I assume the walls are thicker, hence the drywall returns. If you have true double hung, then you should be aware that there is a flange attached to the window which was used to secure the window to the exterior of the house and sits beneath your exterior siding.
Contact a few local window companies and have them come out to your house and provide you with an estimate for windows and install. Explain how you would like to finish it on the inside. They will work with you and provide some options. Lowes, Sears and Home Depot also provide sales and installation support. You do need to worry about flashing and possibly capping if the framing needs to get packeted out to accomodate the replacement windows. Finally, if you still decide you can do it all and simply need capping on some exterior trim, the contact several local siding company (check references!) and have them come out to give you estimates. If your uncertain how this all will work, at the very least have aprofessional do a few for you so you can see the process and decide if you want to undertake this task.

Good luck