Doors and Windows - Replacing older vinyl windows

Hello,

I need to replace (4) older vinyl windows upstairs in my home. It's a 2 story house. It has vinyl siding, no trim on the inside just framed with 2x4's covered with drywall. My window openings are all the same 46"x46". This is the drywall opening.

Can I change them from the inside?

Do I need to remove the vinyl siding, j-channel, top flashing when I change it?

Is 46"x46" a normal size or will I have to have them built?

I think I have that old fiber board siding under the newer vinyl. Not sure if that wil be a problem.

Any info would be great!!

QUADSOURCEMARK

Its hard to tell how the windows were installed without seeing it. They might have a nailing flange that is behind the vinyl siding, in which case, the siding would need to be removed in order to get the old window out. Of course, someone could also have just stuck it into a hole, caulked the edges, then screwed through the frame to secure it (which isn't a real good way to install, but I've seen it done). In short, I doubt you can do it 100% from the inside.

As far as the size goes, there are a few companies that offer vinyl windows in standard sizes, but that varies from company to company and it would be impossible to say what standard sizes you might find. 48x48, or something close to that might be readily available. Otherwise, almost all vinyl windows are custom sized except for the few standard sizes you might find in a big box store.

Now I'm wondering if they put vinyl over the old siding and left the windows in place. flashed over the top and put up the siding. That could be a job if the windows are flanged under the old siding. Any idea what a basic window 46"x46" installed x4 windows?

Thanks for your help,

If I measured stud to stud it would be closer to a 48"x48" window. My current measurment is the window opening complete with drywall.

thanks.....

>>Any idea what a basic window 46"x46" installed x4 windows?

I'm not quite sure what you are asking? an idea what 4 windows that size would cost? My guess would be $650 x 4 = $2600 including installation, for a good quality window and professional installation.

Sorry I wasn't better with my questions. You've been very helpful.

Thanks...