If you are environmentally conscious and want to build to last consider the engineered wood products that are available.
1. OSB (oriented strand board) is an engineered plywood replacement that been improved vastly over the years. It is cheaper than traditional plywood, has similar strength characteristics, and is made with scrap wood and small new growth trees which make it a sustainable product.
2. I-Joists are replacements for traditional dimensional lumber such as 2x10 Joists and rafters. The beauty of I-Joists is the fact that they can handle greater spans than traditional joists, they are a green product since they contain an OSB web and a 2x3 top and bottom chord, they are lighter and easier to build with, and they maintain there size without the shrinkage that is typical in dimensional lumbers which can cause aggravating and expensive plaster and paint repairs in new construction.
3. LVL's (laminated veneer lumber) are a beam product that are often used for the center beam's in home construction or in areas that require a large span opening. In many cases where we "blow out" a bearing wall we will put an LVL in it's place to carry the existing loads. The advantage of LVL's are similar to I-Joists. They are green, they carry greater loads over greater spans than dimensional lumber and they offer less shrinkage. They also give the option particularly in basements for the use of less bearing columns which can aid in the design of finished basement space.
These are but a few of the products that are available but are probably the most prevalent. Know that these are superior products and that any extra $$$ spent up front on these products will be saved on the back end of your projects in costly repairs to paint and plaster due to the unstable nature of todays dimensional lumber.
Get Smart and Green! Go with engineered wood!