Once again, some thought provoking writing from longtime sustainable architect and Treehugger columnist Lloyd Alter:

The best way to have our buildings use less energy is to insulate them really well. But for a long time, I have also been writing about the problems of insulating with plastic foam, even writing that Polystyrene insulation doesn’t belong in green building.

There were a number of reasons, including the fact that they are full of dangerous fire retardants, that the blowing agents were serious greenhouse gases, and that they were made from fossil fuels. That’s why I have often written that it is better to build foam free.

Green building is a series of tradeoffs and compromises. Remember, the greenest building is one that already exists.

Sustainability ultimately becomes a value engineering exercise — it’s just that not all of the “values” being engineered necessarily have to do with money or profit.

EPS foam can be a wonderful insulating material that can reduce the energy usage requirements for a building substantially. In the same way, phthalates and bitumen can make for some pretty impervious and resilient waterproofing materials. The dominance of vinyl over aluminum framed windows in the residential markets for the past couple decades have virtually eliminated claims of defective manufacturing, plus they tend to perform much better.

So in order to reduce our reliance on fossil fuels, we need to rely on byproducts of the production of fossil fuels. No easy answers, to be sure.