The 2013 Energy Code update has raised the bar for energy conservation in California.
Along with the update, the California Energy Commission has strengthened Home Energy Rating System (HERS) requirements for Quality Insulation Installation (QII)/Building Envelope Leakage.
QII can deliver one of the biggest increases in calculated building performance in any California climate zone. California’s rules for calculating heat transfer in insulated walls assumes that insulation will be installed poorly. When claiming HERS-verified Quality Insulation Installation, the energy model can use the full R-value of insulation when performing calculations. Depending on the climate zone, a single-family residence could see an improvement of up to 6-10% in its energy score.
For 2013, the already rigorous QII procedures have been revamped to ensure a tighter building envelope, uniform insulation installation techniques and reduced thermal bridging.
The following updates are required for QII:
- Floors – Bottom plates shall be sealed to concrete foundations. All gaps and openings in raised foundations shall be caulked and sealed. All plumbing and access hatches shall be sealed.
- Ceilings – Each ceiling penetration leading to attic space must be gasketed, caulked, foamed, taped or otherwise sealed. All recessed lighting fixtures must be airtight, insulation capable (IC/AT) and sealed to the drywall.
- Wall cavities – All gaps in stud bays must be sealed with insulation foam, caulk, or other approved means. Gaps between framing and windows or doors shall be sealed with minimally expansive foam.
- Knee walls – Shall be treated like any other stud bay and sealed.
- Batts – Voids, gaps, and compressions of any kind are no longer allowed. However, a paper-faced batt with inset stapling is allowed as long as the void does not exceed two inches from the face of stud inward. Batts shall be cut to fit snugly within the stud bay, split around all plumbing and wiring, and be in contact with all six sides of the stud bay.
- Spray Polyurethane Foam (SPF) – Two types and applications:
- Low Density Open-Cell SPF (ocSPF) – Shall be installed to a nominal density of 0.4 to 1.5 pounds per cubic foot.
- Medium Density Closed-Cell SPF (ccSPF) – Shall be installed to a nominal density greater than 1.5 to less than 2.5 pounds per cubic foot.
- Blown-In – Attic rulers shall be used in attic spaces with blown-in insulation.
- Insulated Header Requirements
QII now requires that headers be insulted to minimize thermal bridging. Often load-bearing headers may have no insulated qualities, which leads to excessive thermal bridging. The code now addresses the issue:
- A two-member header is required to have insulation, minimum R-2 between the headers.
- A single-member header less than depth of wall shall possess an insulated panel, minimum R-2, on the interior face.
- No insulation is required for a single-member header that fits the depth of the wall (for example, 2×4 wall with 4x nominal header).
Installation has very strict protocols that often challenge project teams that have not experienced the standard. With stricter standards, it is increasingly important to include your HERS Rater early on in the construction process if QII is specified.
For questions about the new QII standards and other green building project issues, including LEED and CALGreen, please contact:
Director of Sustainability