The design incorporated a complete energy envelope to reduce the long term operational costs of the building for this owner occupied structure. Instead of compliance to the local 2003 IBC the design incorporated all provision of the 2015 IRC into a commercial structure raising the performance bar since houses must meet higher energy requirements over commercial buildings. Included in the design was a radon/moisture barrier material (recycled 20 mil vinyl billboard sign face material) that covered an R-20 EPS insulation system to close the energy envelope under the structure.
The ICF portion of the structure cost less than wood frame construction that would require moisture and air barriers along with the addition of 2 inches of exterior foam for a comparable R-Value. Examination of the total energy envelope for any structure has determined that for comparable performance ICF can be cheaper than wood frame plus all the additional pieces necessary for code compliance.
The walls incorporated Quad-Lock Building Systems R-30 wall system with 4 inches of foam exterior of the concrete surface and thus moved the dew point exterior of the concrete plus creating a thermal bank area to buffer temperature swings.
The building used recycled billboard reinforced vinyl sign faces to provide a sealed crawl space moisture/radon barrier membrane that was 20 mils thick instead of industry standard products. The energy envelope design has reduced the sizes of the mechanical system and heat loss from the structure with a HERS rating of 55 that residential homes try to obtain. Because of the ICF wall product, sealed crawl space and attic along with the fixed window glazing the air infiltration entering the building was less than 1 ACH50. Although this is a residential test it allowed the mechanical system design to perform better than calculated due to reducing the cooling demand by 30%. Heating demand is just starting to be examined due to completing the building in October. Use of cement based stucco further provided a low maintenance surface decreasing exterior surface degradation and extending the design performance.