Window Replacement vs. Adding quiet windows

New windows -- stop the drafts, get tilt-in cleanables if you don't already have them, choose the interior color that you like (which presumably isn't the mystery-metal brown that's so popular in 1980s replacement windows). White. Be sure to do "brick-to-brick" or "new construction" and not what are sold as "replacement" windows. Those will be smaller and you'll lose glass area.

... and you can always add a second set of windows on your sill if the replacement windows don't do the sound reduction trick.

Be sure to address noise infiltration from through-wall ACs, and if you put a second set of windows in, have a plan for window ACs (if any)

I've had neighbors who installed the same windows (in the same building). One had no relief from the drafts and outside noise because the installation/sizing of the windows was not good. The other's windows were perfect.

I installed CitiPROOF windows in my last apartment. They need a 3" gap between the two windows. They can do a "build out", framing around the outside of the window (interior wall side) when the window sill is too small. I was lucky and was able to fit my plants between the two windows. The plants did very well.

After going through a similar decision, I ordered replacement windows from Skyline - they offer single and double-laminated windows. The lamination (layer of plastic sandwiched between sheets of glass) reduces noise at the cost of a very slight tint. The noise-blocking factors they quoted were STC 39/OITC 31 for single lami 1" and STC 42/OITC 33 for double-laminated 1 1/4" (which I'll use in the bedroom). I think interior windows offer even greater noise blocking, but I wanted nice picture windows and not to lose interior space.

Just hang your plants, get CitiProof windows and live happily ever after.

Thank you, jelj13 and levliko. Would you mind telling me what the prices were? a ballpark would be fine. Just trying to get a sense of whether one is significantly more than the other.

Alanhart - we do have window a/c which is definitely part of the noise issue. Any suggestions on how to address that if we did replacement windows? I think if we did second set of windows, it would cover the A/C in the winter and hopefully the noise of the a/c in summer would help drown out some sound.

A lot. As in over 9 Gs for four windows (2 large, 2 narrow). And other contractors offered similar or higher prices. Large tilt-and-turn picture windows are amazingly expensive -- double-hung would be cheaper, but the panoramic effect of 6x5' glass justified the cost for me. :)

By the way, a friend of mine (with her father's help) did the installation themselves for a second set of perfectly normal HD or Lowes-ordered double-pane windows, and it helped tremendously. I'm not sure if Citi or any other company does anything more than that.

Think through how an interior window will affect the cleaning of the exterior of your outside window ... can it still tilt in with the interior window in place? Or can you easily remove the interior sashes to allow the exterior to tilt in?

homehunter: your winter/summer plan makes sense. I don't know if there's anything more that's done besides that. But I'd like to know.