Replacing 2 Single Hung Side-By-Side Windows

I'm going to replace 2 side by side single hung windows. I realized they are only separated by the original windows frames, about 1.5" or so. I'm assuming if I replaced the windows with two dual hung I would need shorter screws and drill new pilot holes in one of the windows (assuming the holes are in the same spot on both windows) to prevent the screws from hitting each other. To replace the windows with two double hung, is this ok to do? Will the existing frame provide enough support between the windows?

If it's not too much trouble to remove the center frame, I'm also looking into a single 3-Lite or a double slider. Would a 3-Lite look ok in a 72" opening as the sliders would only about 18" (minus vinyl framings)? The full opening is 35"x72".

I generally like to remove that center bar and install a factory mulled (assembled together) unit. You will get a better seal that way imo, as well as more glass area. You'll just need to add a some woodwork to cover the holes that are left on the sill and the head... Some people like to keep it though, and that is fine too. If you use the factory supplied fasteners, you shouldn't have to worry about any pilot holes or interference. Just install as normal. 72" is fine for a 2 or 3 lite slider if you want to go that route.

Thanks HomeSealed for the reply! I'm a little confused about using the supplied screws & holes, it seems like they are long enough (according to the screws that came with another window) where they would go though the other window's frame and/or interfere if the screw holes are in the same location on both windows.

Otherwise, that's what I wanted to hear, that the existing frame would work. But I do like the idea of a better seal and possibility a full 72" window. I'll have to remove the rest of the trim and see home much woodwork it will take to patch up the holes. The sill is angled, so I'm not sure I want to patch that but otherwise hopefully it won't be too difficult.

Actually, now that I look again, you may not need any woodwork. It looks like the top and bottom stops run all the way across instead of butting up to the mull trim. You would just need to add paint. .... On the screws, Ive never had that happen. To be honest , I've never actually measured, but I've never had that happen on hundreds of windows with a similar setup... What size screws did you get? 2 1/2"?

Yeah, it looks like the I should be able to cut out the center window fames. The rest is cosmetic trim. Thanks for your help!

No problem, good luck on the project!

If you do a twin DH or SH and it is factory mulled the screw length is a non issue, if you join them onsite and it is a c mull still a non issue, only if you use a H mull would you have the screw length problem, if you are smart enough to do the install and understand the afore mentioned explanation you are smart enough to figure out what to do about the screw length.
If we cut out a vertical mull the sill is usually continous but the head is not, I usually run a couple of long screws through the jamb into the framing to strenghthen.

I know I'm jumping in late, but the last time I replaced 2 side by side double hung windows, I build a deck outside the windows and replaced them with a sliding glass door.

When we moved into my current house, there was a pair of double hungs looking out over the back yard. Due to the slope of the lot, the yard is 6' below the floor level of the room.

The only ways to get to the back yard was to either go out the front door and around to the back, or down the basement stairs - which landed at the front of the house - and then make U-turn, go all the way through the basement and out the back door.

I told my wife that the only way I'd buy the house was if the very first project was to build a deck and replace the windows with a door. We moved in in April and broke ground the next weekend.

The family before us had lived in the house for 30 years and rasied 4 kids, all that time dealing with inconvenient access to the back yard. It's been 25 years since I built the deck and we still love it.