We lived in Madison for ten years and our older home had double pane casements windows by Anderson and worked beautifully. We painted them and there was no problem with them.

New windows are so much better than old windows. If you are living in CA go to Lowe's or Home Depot and allow them to educate you on windows; the windows made today are really nice now and at reasonable prices. I think you might want a contractor to check out your Mom's house; get references from Angies List and go from there.

These days you can get almost anything you want (if you're willing to pay for it). Dual pane insulated single or double hung windows are what I see most of out here. You can do triple pane windows as well, but here in the south of the state I haven't seen them yet. Make sure the frames aren't metal. The double hung windows are what I would go with since they're the easiest to clean and will most easily create a nice breeze in the summer.

I would also suggest going to an independent supplier for your windows, rather than a big box store. Many companies have a different, lower end product just for the big box stores.

You might also consider a possibility of a Tax Credit for new windows. I am not sure if any program like that is being offered but it is worth contacting the energy departments in your Mothers area; they would probably know if credits are available.

Our daughter did a remodel a few years ago and they ended up taking out half of the windows in the house and replacing them with fewer but larger windows and really cut down on the heat escape and ac escape. A good contractor can guide you; often times a 'window' person only knows about windows and not the whole energy heat/air exchange for the house. That is why I suggested a building contractor via Angie's List. Also any window store can give you info on energy efficiency etc. The triple panes do not conserve that much more energy to off set the additional price. Also some companies make a vinyl clad wood window that maintenance free, with tilt in windows for ease of cleaning. I guess I am saying, winter is coming in WI and this takes time and research when you are spending this much money. Good luck.

You might also want to have the contractor check insulation in the house attic area. That has come a long way too and makes the house cozier if you need more.