Exterior Insulation and Finish Systems (EIFS) are a type of building product that provides exterior walls with an insulated finished surface, and waterproofing in an integrated composite material system. [EIFS is pronounced "eye-fuss" or more recently "eyefs"]
Some EIFS manufacturers tout the material as extremely Green. It does provide an insulating value that is generally better than most other building systems. The materials are lightweight, so transportation should use less fuel. But there are several features of EIFS that do not seem Green to me - durability, the manufacture of foamed polystyrene and recyclable materials. I think EIFS has a place. I think the marketing folks are overselling the Green aspect of EIFS.
EIFS does not last forever. Let's say forever is 100 years. The EIFS that I am familiar with and that is over 20 years old has been re-coated or replaced. If you know of EIFS that has lasted untouched for 40 years, about the age of the industry in the US, I would be surprised. Even so, I think it is implausible that EIFS can last 100 years without additional time, money, and energy being required.
EIFS uses polystyrene as the base material for the synthetic stucco finish coat. The polystyrene is a good insulating material, having an R-value of 4 per inch of thickness. It is a better performing insulation than fiberglass and so preferable. But polystyrene is not an entirely Green material. Expanded polystyrene is made from petroleum and may use blowing agents that are greenhouse gases. It is not biodegradable - floats and blows around. If it ends up in water or land habitats, it is harmful if ingested.
The foam insulation that is part of EIFS is difficult to recycle. Consumer polystyrene is generally not recycled curbside, but is fairly easy to recycle it at the industrial level. So the product could contain recycled polystyrene, but very little of it is recycled in the US. (Polystyrene is recycling designation 6.) One EIFS manufacturer suggests that it be ground up and used as a soil amendment in your garden. The same manufacturer boasts that all the EIFS they have installed would build a wall from coast to coast 150 feet high! I don't think it will be recycled when it is removed, because no one is set up to separate the polystyrene from the synthetic plaster. I don't think it will end up in your garden; I think it will end up in a landfill, a large landfill.
As I said above, I think EIFS has a place, but I don't think EIFS is the solution for every building. And I definitely think the marketing efforts to portray EIFS as an extremely Green building material are misleading.
Research for this article was done using Wikipedia.