I opened up the sash balance mechanism by grinding the staked keepers that hold the cover in place. Then inserting a putty knife into the housing (had to bend the end cover up for access) and over the spools (to protect them), then a flat screwdriver on top of that knife and turning it to pry the cover free. Not much pressure is required, if you have ground enough of the staking away. I was then able to replace the broken cord with some nylon masons line. I wound the new line around the drum and used it to rewind the spring, repeating until it looked like the other one that was not broken. I then used a small c-clamp to keep it wound and proceeded to place the correct number of wraps of lines on the drum to duplicate the unbroken one (total of 3 ½ turns). Then threaded the line out through the hole in the housing and through the plastic pellet and tied a big knot in it. Then released the c-clamp, while holding the spool with my thumb, and slowly allowing the tension to pull the plastic pellet into place against the housing hole. (I wore work gloves during the rewinding operation so I could safely hold the spool with my thumb when needing to do subsequent rewinding on it. From past experience replacing tape measure tapes, I was careful to watch for and avoid the spring going ballistic on me. It never really threatened to though.) Then I replaced the cover so that the ground away posts were in the opening where they belonged and taped the cover on with USPS packaging tape. :) The cover isn't in danger of coming off since it's held in compression when in the installed position. I wish I had been able to find some heavier line but I think the masons line will likely last well enough. It's rated at 155-pound test. If it doesn't, there is a heavier masons line available that is 216-pound test that I'll replace it with. A tip getting that left side track back into place without breaking it or hurting yourself is to slather some liquid dish soap onto the window stud. It slid right into place easily after I resorted to that method. It also helps to file the sharp end of the spline on the back of the track so it doesn't gouge into the stud. It has taken me nearly as long to post this than to replace the broken sash cord line. I hope it helps someone like me who couldn't find any info on doing this and had to stumble through it. I like fixing things rather than tossing them, especially when it only needs a piece of string replaced. YMMV

7'3" is pretty big for a casement. When open, that size sash would put a lot of pressure on the hinges & operator. If you are leaning toward casements, and don't mind tearing the old frames back to the studs, then you might want to consider casements with transoms. Most manufacturers have the ability to provide detailed drawings of window combinations, so experiment with styles that might interest you.

The reasoning behind this is the manufacturer doesn't make a good DH unit. The vinyl DH's need to be better built and stronger than the others. Anytime you have two fully functional sashes you require a more precise installation with more patience. The Single Hungs are just cheaper to make and easier to hang. Almost idiot proof in most cases. They are also more energy efficient from air infiltration becuase a lot of installers don't take the time to shim the DH unit properly. They end up leaking around the sashes, creating that ever so hated call back. With a stationary top sash they don't have to worry about anything leaking around the upper sash. The downfall of the SH is you can't tilt the sash in for cleaning. This can be quite trouble some for the windows off the ground a ways. There are ways around that for cleaning if shown the proper way. The history of the DH window goes back to the old farm houses that never had AC or Central Air. They would pull the top sash down about six inches and the lower sash up about six inches. This would let the air circulate better in each room by creating the drafting affect (Firefighters call it breathing during a house fire). With todays AC in almost every house the DH windows aren't really required for the drafting situation. You can still get them from almost every dealer. If they are balking at DH's with reasoning like they gave you. I would steer clear of them and start shopping for another supplier. Hope this makes sense to you. God Luck!!!

benjesbride , your layout looks nice. The back run of cabinets is about 22' plus another 12' for the island and 5' next to the fridge. Is that a lot of linear feet of cabinets? I like the idea of opening the dining room up and moving the entrance to the center at some point in time. Would love to do it right away, but I'm not sure what the rest is going to cost. Our window guy is stopping by tomorrow to give us a price on replacing the bay with other indows (double-hung, casement or sliders). I know the new bay would be almost $3,900 so I am hoping for a quote that is much less than that. I am also meeting with a KD tomorrow who, based upon our conversation, will most likely be proposing something like this photo. I am not sure what I think about it, but know that he has actual photos of other kitchens with a similar layout. What do you think? I still think the bay causes a problem.