White spruce was a great favorite of northern New England framers in the late 18th and early 19th Centuries. I began my timber framing career around 1970 building in old growth white spruce and would enthusiastically recommend it as strong, light and generally well behaved (apart from a tendency to check, and for some pieces to twist after drying). I would stay away from bully, pasture spruce, but if you can get good, clear forest trees, you should do fine. Take care to end seal all end grain surfaces and avoid storing timbers in the wind or direct sun if possible. And watch out for spiral grain.