I always balk at using heavy wood, ie, spruce 1/8" sq instead of balsa 1/8" sq. My mentor showed me that one can carefully choose a length of 1/4" sq that weighs less than the spruce 1/8" sq, ie increasing the SECTION (and strength) by 4 and reducing the weight! I built a Bristol Scout using that philosophy, and the thing was feather-light, and very, very durable (I used it as a trainer!).
Remember it ain't the crash the destroys the airplane, it is when the tail catches up and stomps all over the fuselage. One CAN build light, but strong.
I have built a few Brit kits; their access to quality wood is limited, so they design for lots of space in between components, and space don't weigh anything!