The main house, in particular, is exceptionally transparent. Its copious windows—some are as tall as 12 feet—"pull in the views and make it feel a part of the natural setting," Tage notes.

When Jake Hurwitz, 32 and his fiance Jillian Vogel, 27 moved into a 1965 A-frame cabin in Mt. Washington last year, they worked with designer Jennifer Wallenstein of September Workshop to give the ...