What's "un-sustainable" about how we build homes now? Sustainable building takes into consideration how a building performs over its life cycle. The word "sustainability", to me, refers more to resources...
The word "sustainability", to me, refers more to resources and to how the building performs over its life cycle. That means what happens before the building is built and what happens after the building has expired. It's a complete life-cycle view from the cradle to the grave, so to speak. How much concrete had to be manufactured to pour the foundation? And what goes into the manufacture of concrete? First of all, lots and lots of petroleum is burned, so you're paying for that house right up front with a non-renewable resource. When petroleum's gone, we'll be looking at this concrete as an investment. And it's not a bad investment. I'm not knocking concrete, because it's an amazing substance for what it is. For foundations, it's hard to beat. But a lot of energy does go into its production. Part of sustainable building is also about design. It's about making sure that when that foundation is designed, it's designed correctly to stand up for a long time. Concrete has the potential to do that if it's correctly sided and placed. If proper thought has gone into the placement and design of the foundation so that the building has a really long life cycle, that can be a very good investment even though it's very energy intensive.
On the other hand, let's take the masonite siding from the 70s that only lasts for a few years. That siding also takes a considerable amount of energy to manufacture. Not only does it take petroleum to manufacture it, but also wood fibers and other chemicals that are added to press it. As few as five years after it was installed, some of that siding that wasn't installed properly rotted and fell off. Bad investment. Not sustainable. But there have been some strides in more sustainable siding material such as hearty plank siding. It lasts a long time. It's made of concrete and fibers, but it's a better engineered product. Carpet is another example; not very sustainable at all. A lot of people will decide that they don't like their carpet after five or ten years and will get rid of it. You have to throw it away. That's not sustainability. Asphalt roof is another one. I don't know what percentage of our roofs are made of asphalt shingles in the U.S., but it's very high. It's the worst thing you can build a roof with, especially in the south. It's a heat sink - it holds heat - and it's a disposable roof. It's only designed to last 20 years. It's also not recyclable. Metal roofs are designed to last 50 to 100 years and are completely recyclable.
