A house of cards succinctly illustrates the concept of load-bearing walls; every horizontal card must be supported by vertical cards; and as cards build upward, their weight bears down on the lower walls. A real house works the same way, except that the load-bearing walls aren’t so easy to locate. Identify these important walls using a few rules that apply broadly to buildings before starting your project. Always remember, though, that even if it doesn’t fit one of these cate