Comparative Summary of Building Systems

Here is a comparative summary of available building systems that sufficiently integrate and balance the five criteria for a sustainable Louisiana house and have particular advantages in specific conditions:

• Fully borate- or pressure-treated frame systems (no untreated structural wood and borate-treated rigid foams) are strongly recommended in all of South Louisiana because Formosan subterranean termites are a high risk.
• 2x4 framing with foam sheathing is suitable for all but coastal and tornado areas.
• 2x6 OVE framed homes generally cost about the same as standard framed homes (depending on window area and finishing techniques) with added benefits.
• 2x6 OVE with foam sheathing is especially advantageous in North Louisiana.
• 2x6 OVE framing with structural sheathing is a good option in South Louisiana.
• SIPS are advantageous anywhere in the state (borate-treated). Higher material costs can be largely offset by labor savings for production builders. Typical costs range from comparable to 2% more than standard framing; a large amount of window area erodes cost effectiveness.
• ICF is particularly advantageous in high-wind, coastal and tornado areas, especially when used with borate-treated foam, floor and roof systems in the south. Typical cost is 2% to 5% more than standard framing, depending on relative cost of wood, concrete and labor.
• AAC and insulated masonry construction systems can be good options in coastal Louisiana, depending on local market acceptance, cost and labor. They may be most practical as a barrier system with a stucco finish. AAC and insulated masonry have advantageous properties for warm, high-wind and termite zones that may offset cost and experienced labor availability limitations. Other systems above offer superior insulating performance.