I have my own reservation against LEED (and I'm a LEED AP), it seems more of a marketing scheme than an movement towards green design. It would be a lot more effective to change our building code to incorporate more "green" building requirements.
Your questions taps into some fundamental questions about architecture. Buildings should be designed to stand the test of time, so they should be designed in a manner that they can easily be modified to future uses.
All in all I would argue its on a case by case basis.
That would include the Lumberjacks, the Mills, the Truckers, the Retailers as well as the Contractors and laborers.
Absolutely everything that happens, has a positive and a negative effect on the economy and the environment.
About the only exception to this, for the last 5,000 years, is our garbage.
Think about it.
Or you can buy a condo of your choice. Because of their population density, condo buildings are almost always more efficient than single family homes.
Some answers may be found in this interesting article by Tina Gleisner http://goarticles.com/article/Building-Materials-New-Versus-
Johnson and Johnson Team Realty