Replacing window

[TwinkeeDink]

I'm going to replace a few windows in my house this Spring/summer. What's a for sure method for measuring existing windows so that I can order new ones, without having to start demolition. Don't know how to get an exact measurement for R.O. without tearing off trim, etc.

[Roofer]

Unless it is a standard window size, you have to get to the rough opening. To get that you have to take off the trim or the trim on the outside, depending on your siding. You want to get very good measurements, this is critical. You are going to need multiple saws, nail guns, siding info, etc... to get the project done. Make sure you know what you are getting into.

[sparcebag]

Are your windows installed with drywall,wraped around the interior opening?

If so measure the opening side to side & top to bottom,add one inch for existing drywall,So if a measurement is say 47 & 3/4 inch add one inch RO would be 48 & 3/4 inch.

If its not drywall post again.

Most windows are 1/2 inch clearance of RO so I always figured close is enough Dont need to be exact.

[captainstevo]

Well, The first thing your going to have to do is look at the type of windows you will be putting in, I would suggest not getting new construction, nailing flanges are a pain to get behind siding and so on.

I would then measure the size of the window inside of the jamb and add twice the thickness of the jamb (to account for both jambs) The thicknesses are usually 5/8 but I have seen them as thick as 1 1/2. You can take off one piece of trim on one window to see this if you are not able to tell from the exposed portion.

After subcontracting for a window install company this seems easier than it is. Remember to shim well and insulate the corners well but dont over stuff. not enough insulation will allow air leakage, to much can bow a window and make its operation harder.

I hope some of this has helped and is not ranting, it made sense in my head

[Roofer]

[Surface Tension]

As said, you'll be pulling off the casing(trim)to get the RO.

It doesn't stop there! That new window most likely isn't going to just fit into the exterior opening. Plan on altering your siding and trim. What do you have for siding and how it the window trimmed out?

I was about to list all exterior scenarios that you could have on how to best approach them but got half way through doing that then decided its best that you post a picture.

Another consideration is replacements. If done correctly with a quality replacement and assuming your jamb and sill are good, replacements are a good option.