From Thermotech's website: Firstly a double hung window is not as air tight as a casement window. The double hung window has to slide, so its weatherstripping can't be as tight as a casement or it won't slide. That's obvious to most people. What is not so obvious is that sliding windows aren't as air tight as casements because the weatherstripping changes plane. Think of the bottom sash of a double hung. The bottom and side rails are weatherstripped along the edge of the rail. But what about the meeting rail? It's weatherstripped along the outer face. It is difficult, very difficult, to maintain the integrity of the air seal through this change of plane. Despite the fact that double hung windows are inherently draftier than casements, this does not have a major effect on your annual heating bill. The reality is that as long as new windows can maintain their tested air tightness (this topic will be the subject of a future column) very little of the window's heat loss is due to air leakage. Most of the annual heat loss from reasonably tight windows is from conductivity losses through the frame, spacer and glass. This is where double hung windows really fall down, (so to speak). All sliding windows have inherently cold frames compared to hinged windows, like casements. The sash in a casement window is "insulated" on the inside by the hardware cavity. The sash in a double hung window has no such advantage. Another inherent thermal weakness in any sliding window is the meeting rail. Thermally it is the weakest part of any sliding window. The upper sash in a double hung not only loses heat through its outer face, but also through its lower edge. It is cooled on two sides. That's why the bottom edge of the upper sash experiences condensation before the lower sash.

Thanks for the feedback guys. The look is sixes with me but there is one wall of the home where I absolutely know I want DH because the windows are not easily accessible to clean otherwise. From a "Just do one or another" visual perspective DH would probably win just because of that. Does double hung tend to run less expensive in the Integrity line as well? I'm looking at 6 foot high windows in a few locals and the casements there appear to be standard tempered according to the Integrity catalogue. I'm going to guess that I could maybe get away with untempered DH and probably save some? Mooredb, have you had your jeld-wen windows long? How are they working out? I have to admit the overall opinion of jeld-wen windows on this very forum scared me away early on, tho I think even in the end the wood interior of integrity is worth the premium for us.

Thank you for the advice! If we get double hung windows to replace these they will be a little shorter so the ht-width is the right shape for a double hung window. That will make it easier for furniture placement, actually, which makes me happy :)

I really appreciate all the advise you folks are offering! You're giving me lots to think about that I didn't know and a new perspective on things I did know. yes it does, the narrow meeting rail gives it away, it would be more noticeable if the windows were side by side. I I'm glad you said "narrow" because that made me realize I really need to compare this to the brand/model of DH window I choose, because if the meeting rail is wider, it will be much more noticeable. the encompass is a pretty cheap window, I am not to familiar with there casements so I am only referring to there double hungs at this point. Good to know. The encompass is the one we were looking at for DH and the 250 series for casements. I'm realizing now that our window budget of $11k is probably too low. I had never purchased/priced windows before, so I didn't question the builders number. Now that we are looking at them....I wish I had put some more thought into it. A quick window count and a trip to Lowe's would have caused me to question that a little more. We are supposed to get the builders discount, but even with a decent discount that price would be hard to meet. What other brands does your building supply store carry? I'm not sure. I know they carry Ply Gem, Pella and Anderson. The one time we spoke about Anderson, they said they were about $700/ window, so the conversation didn't go any further. Are Anderson really THAT expensive? Just the screen on the inside (casement) vs the outside (double-hung) will make windows in the same bedroom look different. You would need to use casements in all bedrooms and casements are more expensive than DH's. perhaps you could use an in-swing casement but I don't think they're made in PVC. This is an excellent point. I knew the screens were inside on a casement, but I've been so focused on the exterior view, I hadn't thought about the screens on the interior. I guess I forgot because in our last home all the screens were stacked in the garage instead of on the casement windows. :) Although the casements cost more it might not be any more $ since we were adding windows to the side of the house instead of just changing a DH to a casement.