Trying to budget for new Andersen double hung windows—what should I expect?

I’ve swapped out a bunch of old windows over the years, and you’re right—there’s usually some odd surprise in the framing, but rarely anything catastrophic. I’d budget a little extra for minor fixes, just in case. One thing I wish I’d thought about was trim—sometimes it cracks or won’t go back on cleanly. Have you considered whether you’ll need new interior or exterior trim? That can sneak up on you cost-wise.

Trim’s a sneaky one—sometimes you get lucky and it pops off clean, other times it splinters like nobody’s business. I usually factor in the cost of at least some new trim, especially if your house is older or the existing stuff is painted shut. Caulk and paint touch-ups add up, too.

Trim’s a sneaky one—sometimes you get lucky and it pops off clean, other times it splinters like nobody’s business. I usually factor in the cost of at least some new trim, especially if your ...

I get what you mean about trim being unpredictable, but honestly, I’ve had better luck than not when taking it off—especially if I score the paint line first and go super slow. My place is 70s era and most of the trim popped off in one piece, just needed a little sanding before reusing. Guess it depends if you’re dealing with a ton of old paint layers or not. Caulk and paint touch-ups definitely sneak up, though... those little tubes add up fast.

I actually just went through this last fall, swapping out three old windows for Andersen double hungs. Here’s what I wish I’d known up front:

First, the window price itself is only part of it. I got quoted around $550–$700 per window (mid-range 400 series), but the install was almost as much—labor adds up fast, especially if your openings aren’t standard size. My house is from ‘78 and the old windows weren’t square, so there was extra work shimming and trimming.

On the trim—totally agree it’s unpredictable. I tried to be careful, but a couple pieces split no matter how slow I went. If you’re planning to reuse, I’d score all the seams with a utility knife first and gently pry with a putty knife, not a crowbar. Still, I ended up budgeting for about 25% new trim just in case.

Don’t forget caulk, paint, and a little extra for surprises (like hidden water damage). My “small” project ended up about 20% over my original estimate once all the little things were factored in. Not the end of the world, but it’s good to pad your budget a bit.

That sounds about right—my window project last spring was the same deal. Surprised me how much the little stuff added up, especially trim and paint. I tried to reuse some old trim too but it just didn’t survive. The hidden water damage behind one window turned into a whole afternoon. It’s a pain, but you’ll feel good once it’s done. Padding the budget is smart—better to have a cushion than get caught short.

Funny how the trim always seems like an afterthought until you’re knee deep in it, right? I’ve seen a lot of folks get caught off guard by hidden damage—sometimes the window itself is the easy part. Did you end up going with pre-primed trim or just raw wood? I’m curious if you found one held up better, especially with older houses where nothing’s square.

Funny how the trim always seems like an afterthought until you’re knee deep in it, right?

Every single time. I swear, with my old house (built in the 40s), nothing lines up and the trim is where all the real headaches start. I actually tried both pre-primed and raw wood on different rooms. The pre-primed was supposed to make life easier, but I still had to sand and fill a bunch because the walls are so wavy. Raw wood took more time upfront but I could at least tweak it to fit the weird angles.

Honestly, I didn’t notice a huge difference in how they held up after painting—except the raw wood soaked up way more paint. If you’re dealing with a not-so-square house, I’d say go with whatever’s easier to work with, because you’ll probably be doing a lot of custom cuts anyway.

Did you run into any surprise rot or weird framing behind your old windows? That’s where my last budget went sideways…

- That part about the trim being the real headache is way too relatable.

the trim is where all the real headaches start

- Haven’t found rot (yet), but honestly every time I pry something off, I half-expect to see daylight or some weird squirrel nest. Did you have to replace any framing or just patch up spots?

- My house isn’t as old (1958), but nothing’s square either. Measuring for new windows gave me a headache—one side of the opening was almost an inch lower than the other. Is that normal, or is my house just extra wonky?

- I’m also stuck on whether to go with pre-finished trim or just paint it myself. The pre-finished stuff looks nice, but it’s $$$ and I’m not sure how it’ll hold up after a few years of bumps and dings.

- For those who’ve done this before—did you regret not getting the install done professionally? DIY is tempting for the budget, but I feel like there’s always that one “gotcha” hiding behind the drywall...

Curious if anyone else had weird surprises when they started demo for new windows. Or maybe I just have bad luck with previous owners’ “repairs.”

Yeah, I ran into the same thing with nothing being square—my place is from ‘62 and every window opening was slightly off. Had to shim a bunch just to get the new frame to fit right. Did you notice any weird wiring or pipes behind your trim? I found an old phone line just stuffed in the wall, no clue why.

- Out-of-square openings are pretty much standard in anything older than the 80s, I swear. Shim city every time.
- Found a mystery wire once—turned out to be an old intercom that went nowhere. Made me wonder what else is lurking in these walls.
- Sometimes I see copper pipes running way too close to the frame, which is always a fun surprise when you’re drilling.
- Did you run into any insulation nightmares? I’ve had spots where there was literally newspaper stuffed behind the trim...