2020.0025 2126-2 Prescriptive Worksheet Both Zones 2015 mod - Prescriptive PathPrescriptive Energy Code Compliance for All Climate Zones in Washington
Project Information Contact Information
2126-2 LEVEL DESIGN
253 284-3170
This project will use the requirements of the Prescriptive Path below and incorporate the
the minimum values listed. In addition, based on the size of the structure, the appropriate
number of additional credits are checked as chosen by the permit applicant.
Authorized Representative _________________________________________________ Date ___________________________
All Climate Zones
R-Valuea U-Factora
Fenestration U-Factorb n/a 0.30
Skylight U-Factor n/a 0.50
Glazed Fenestration SHGCb,e n/a n/a
Ceilingk 49j 0.026
Wood Frame Wallg,m,n 21 int 0.056
Mass Wall R-Valuei 21/21h 0.056
Floor 30g 0.029
Below Grade Wallc,m 10/15/21 int + TB 0.042
Slabd R-Value & Depth 10, 2 ft n/a
*Table R402.1.1 and Table R402.1.3 Footnotes included on Page 2.
Each dwelling unit in a residential building shall comply with sufficient options from Table R406.2 so as to
achieve the following minimum number of credits:
1. Small Dwelling Unit: 1.5 credits
Dwelling units less than 1500 square feet in conditioned floor area with less than 300 square feet of
fenestration area. Additions to existing building that are greater than 500 square feet of heated floor area
but less than 1500 square feet.
2. Medium Dwelling Unit: 3.5 credits
All dwelling units that are not included in #1 or #3. Exception: Dwelling units serving R-2 occupancies
shall require 2.5 credits.
3. Large Dwelling Unit: 4.5 credits
Dwelling units exceeding 5000 square feet of conditioned floor area.
4. Additions less than 500 square feet: .5 credits
Table R406.2 Summary
Option Description Credit(s)
1a Efficient Building Envelope 1a 0.5 0.5
1b Efficient Building Envelope 1b 1.0
1c Efficient Building Envelope 1c 2.0
1d Efficient Building Envelope 1d 0.5
2a Air Leakage Control and Efficient Ventilation 2a 0.5
2b Air Leakage Control and Efficient Ventilation 2b 1.0
2c Air Leakage Control and Efficient Ventilation 2c 1.5
3a High Efficiency HVAC 3a 1.0
3b High Efficiency HVAC 3b 1.0 1.0
3c High Efficiency HVAC 3c 1.5
3d High Efficiency HVAC 3d 1.0
4 High Efficiency HVAC Distribution System 1.0
5a Efficient Water Heating 5a 0.5 0.5
5b Efficient Water Heating 5b 1.0
5c Efficient Water Heating 5c 1.5 1.5
5d Efficient Water Heating 5d 0.5
6 Renewable Electric Energy 0.5 *1200 kwh 0.0
Total Credits 3.50
*Please refer to Table R406.2 for complete option descriptions
Table R402.1.1 Footnotes
For SI: 1 foot .= 304.8 mm, ci .= continuous insulation, int .= intermediate framing.
a R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity
which is less than the label or design thickness of the insulation, the compressed R-value of the insulation
from Appendix Table A101.4 shall not be less than the R-value specified in the table.
b The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed
fenestration.
c "10/15/21.+TB" means R-10 continuous insulation on the exterior of the wall, or R-15 on the continuous
insulation on the interior of the wall, or R-21 cavity insulation plus a thermal break between the slab and
the basement wall at the interior of the basement wall. "10/15/21.+TB" shall be permitted to be met
with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the
interior or exterior of the wall. "10/13" means R-10 continuous insulation on the interior or exterior of
the home or R-13 cavity insulation at the interior of the basement wall. "TB" means thermal break
between floor slab and basement wall.
d R-10 continuous insulation is required under heated slab on grade floors. See R402.2.9.1.
e There are no SHGC requirements in the Marine Zone.
f Reserved.
g Reserved.
h Reserved.
i The second R-value applies when more than half the insulation is on the interior of the mass wall.
j Reserved.
k For single rafter- or joist-vaulted ceilings, the insulation may be reduced to R-38.
l Reserved.
m Int. (intermediate framing) denotes standard framing 16 inches on center with headers insulated with
a minimum of R-10 insulation.
Table R402.1.3 Footnote
a Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source or
as specified in Section R402.1.3.