The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standard 90.1 defines continuous insulation (CI) as insulation that is continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior, exterior, or is integral to any opaque surface of the building envelope.
In cavity insulation systems, traditional stud framing can account for at least 25% of wall area. When the studs are uninsulated, there is enough thermal bridging to drop the R-Value from 19 to 12.5 – nearly a 35% loss, which can render any additional layers of insulation useless.
Building codes have higher requirements for cavity insulation to make up for the uninsulated studs or framing members. That is why basement wall code reads 10/13 in many climate zones. It can be R-10 continuous insulated sheathing on the interior or exterior of the home or R-13 cavity insulation along the interior of the basement wall.
Changing Energy Codes
New building codes are increasing R-Values minimums every 3-5 years so that new houses are will not be obsolete or un-affordable 30 years from now due to escalating energy prices. The projected codes for 2030 demand R-Values up to R-30 and the push toward net-zero housing is becoming a reality. While these codes are well-intentioned, they don’t always figure a return on investment into the calculation.
To prepare for rising costs and changing energy environments, you may need to exceed your current local energy codes. See the links at the bottom of this page for information on Climate Zones and changes to the International Energy Conservation Codes (IECC).