Replies

1. GBA Editor
   Martin Holladay | Nov 10, 2009 08:25am | #1

   Andrew,
   Don't confuse EPS (expanded polystyrene) and XPS (extruded polystyrene). You're right that Architectural Foam Supply makes components out of EPS; however, you misidentified EPS as extruded polystyrene when it is actually expanded polystyrene.

   Many green builders feel that the use of either EPS or XPS as an insulation is justified, since these insulation products can lower the energy use of a building over the lifetime of the building. Other green builders are concerned about HBCD, a flame-retardant chemical added to EPS and XPS. (For more on the HBCD controversy, see "Does Polystyrene Insulation Belong In a Green Building?"

   When it comes to the products manufactured by Architectural Foam Supply — namely "columns, capitals, bases, arches, moldings, window sills, brackets, wall caps, pediments, balusters and louvers" — it's much harder to justify the use of EPS or XPS than it is when these foams are used for insulation. Basically, this company sells geegaws designed to mimic traditional architectural elements. Obviously, alternatives exist for all of these products; for centuries these products have been made of stone or wood. Many of these products can simply be omitted.

2. 
   Andrew | Nov 10, 2009 01:14pm | #2

   Thanks for your clarification on EPS vs. XPS. I am building a green home for a client who whats to use decorative moldings and for budget reasons the foam covered with lath and stucco is the a good price point. I was trying to find a "green" version of this foam. The traditional alternatives of stone or wood are too costly for this project.

3. 
   Riversong | Nov 10, 2009 08:18pm | #3

   Andrew,

   Since there is no agreement about the definition of "green" in the building trades, you might want to let us know what that term means to you.

   As Martin suggests, if "green" means only energy-efficient, then you could rationalize using petrochemical foams to save future petrochemical fuels, though the "payback" period of the embodied energy needs to be considered as an energy liability. But if "green" means healthy for both occupants and the local and global environment, then it's difficult to justify the use of any plastic material in a home.

   Your client wants architectural detailing on the cheap. There is no cheap shortcut to a truly green conventional home. Trade-offs need to be made. Green, fancy and cheap do not equate.