Residential New Construction (NC): Slab Insulation UES Measure Update Regional Technical Forum March 18, 2014

Residential NC Slab InsulationResidential NC Slab Insulation: Measure Overview Current Category: Proven Current Status: Under Review Current Sunset Date: April 30, 2014 Reason for Update/Review: Response to recommendation memo; update with latest SEEM calibration Baseline Type: Current Practice 2

Staff Highlighted Areas None 3

Summary of Updates Recommendation memo updates made – Updated workbook to use latest ProCost template – Updated workbook to include complete SEEM model inputs and outputs for each scenario investigated – Clarified measure definition as only applicable to Montana and Heating Zone 3 – Recalculated savings using the updated and calibrated SEEM Version 0.94 – Updated baseline inputs to reflect the latest Montana Energy Code – Removed extraneous SEEM runs from workbook 4

Summary of Updates (continued) Recommendation memo updates not made directly in measure workbook – Documentation of SEEM calibration This documentation is captured separately on RTF website – Documentation of all new construction SEEM inputs Staff has created a centralized workbook with New Construction baseline assumptions Slab insulation measure workbook contains detailed documentation of SEEM inputs relevant to the measure 5

Current Montana Code for Slab Insulation If foundation is slab-on-grade, and slab is less than 12 inches below grade: – Code requires R-10 slab insulation on perimeter – Insulation needs to extend 4 ft by any combination of vertical and horizontal placement (see next slide for illustration) 1 If slab is greater than 12 inches below grade (e.g. full basement), no slab insulation is required 6 1 Applies to slabs without in-floor heat. Heated slabs required R-15 slab insulation by MT code.

Current Montana Code for Slab Insulation (continued) 7 Slab-On-Grade Code Options Vertical caseHorizontal case Combination horizontal and vertical case

Current Montana Code for Slab Insulation (continued) 8 CaseFoundationContinuous Slab Ins., R- Value Perimeter Slab Ins., R- Value Perimeter Slab Ins., Depth Perimeter Slab Orientation Baseline (code) SlabR-0R-104 ftHorizontal, Vertical EfficientSlabR-10R-51 ftVertical Baseline (code) Heated basement R-0 0 ftN/A EfficientHeated basement R-10R-51 ftVertical Baseline and Efficient Cases Modeled

Summary of Changes to Savings, Cost, and TRC Savings – For heated basements, savings changed by -30% to +50%, depending on HVAC system type – For slab-on-grade, savings changed by -60% to +5%, depending on HVAC system type No change in incremental costs other than adjustment from 2008$ to 2006$ All measures remain cost-effective 9

Decision “I _______________ move that the RTF: approve the Residential New Construction: Slab Insulation measure as a Proven UES; Set the measure status to ‘Active;’ and Set the sunset date to December 31, 2016.” 10