I do a lot of re-modelling for myself and for others. Sometimes paid, sometimes volunteer. In almost every case, there is demolition involved before the new can be built. I watch, on rare occasion, some of the HGTV shows, although they are so formula driven, and what I see is a HUGE roll off dumpster parked in the drive and literally tons of stuff being thrown away. OK, it is a TV show and they are always on severe time restraints, (it's part of the "formula") and I wince.
Whenever I demo a house, deck, barn, shed, garage, commercial building or whatever, my mind is always whirling with seeing how we can save rafters, windows, doors, studs, siding, even sheet goods. I even toss pulled screws into cans. All those items are horrendously expensive to buy and there is no difference, none, in framing with clean, dry, re-cycled studs, rafters or joists against using new. In some cases, it is better because the old wood is dry.
Sure, it is inevitable that broken, split or rotten materials have to be pitched. But yes, there is a tremendous about of pride is salvaging all that useful material. That it is "green" is a plus, that it is economical and is common sense. Frugal, indeed. There are ReStores popping up which have taken note and re-sell surplus and culled building materials. Love those places.