Hi,
Thanks for your question about our Port Ludlow House. I suppose that in Alaska you might want to consider triple-insulated glazing, though it is quite pricey. I can tell you that our recently-completed Mazama House is located in the North Cascades, and winter temperatures are often around zero. The house has large glass areas, but the radiant floor heat keeps it very toasty. See:
http://www.houzz.com/projects/230512/mazama-house

Thanks for that. Yes, I currently use a great triple-paned, glazed, insulated window, made locally. I can definitely tell the difference from the older wood double-pane windows (un-insulated).

While my current home was built as post and beam, if I were to build I would most definitely implement radiant floor heating as I just did in my studio shed this summer; it's proving to be very efficient. Although the type of in-floor heating I would prefer (in a slab) becomes more tricky when accounting for frequent earthquake activity.

Thanks for the info!

You are very welcome. A few more points. At the Mazama House, the large windows allow for passive heating of the concrete radiant slab. Also, we typically insulate ceiling construction to at least R-50 and walls to R-38. Finally, during the daytime there is often no need for any electric lighting whatsoever, thus creating another energy-savings.
--Nils