[RCGA]

I need to replace 3 old single paned windows. All three are just like this and I'm 99% sure it's original to the home from the late 1960s

I don't really care if it's an exact size replacement. I'd rather just buy something off the shelf and make it fit rather than a custom sized replacement.

Any ideas on how to replace this? Should I box out with pressure treated 2x4s?

 

[Thunder Chicken]

Knowing the size of the windows would help. How are the walls framed?

 

[RCGA]

40" wide, 23" high, concrete to concrete

 

[cmorales]

Did you approach or call your nearest carpenter to fix the old window frame?

Do you have any handy tools like hammer and other carpenter tools?

 

[Thunder Chicken]

If you can get something close to the right rough opening you could mortar the window in.

Something like this:

 

[Windows on Wash]

We usually tear them out block to block, set in a PVC buck frame on the jambs, and then screw the new unit into that.

 

[throrope]

Believe it or not, made to fit vinyl windows are easy to come by. Many makers and methods. Even the big box stores can hook you up. Follow directions, no short cuts, measure three times and place your order. Custom sized is easier to install.

I replaced a house of cord counter weighted double hung windows with Window Wizards standard product. While most agree welded frames are preferred over mechanical joints, my mechanical joint double pane windows came with the best warranty and were the most economical choice. Now twenty years later I drive past to admire my handiwork. The windows are still there and outlived the warranty.