Prescriptive Energy Form - Building C2018 Washington State Energy Code – Residential
Prescriptive Energy Code Compliance for All Climate Zones in Washington
Prescriptive Path – Multifamily 2018 W ashington State Energy Code-R 1
Project Information Contact Information
Instructions: This multifamily project will use the requirements of the Prescriptive Path below and
incorporate the minimum values listed. Based on the size of the structure, the appropriate number of
additional credits are checked as chosen by the permit applicant.
Authorized Representative Date
a
R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity that is less
than the label or design thickness of the insulation, the compresse d 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.
c
"10/15/21 +5TB" means R-10 continuous insulation on the exterior of the wall, or R-15 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 +5TB" 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. "5TB" means R-
5 thermal break between floor slab and basement wall.
d R-10 continuous insulation is required under heated slab on grade floors. See Section R402.2.9.1.
e For single rafter- or joist-vaulted ceilings, the insulation may be reduced to R-38 if the full insulation depth extends
over the top plate of the exterior wall.
f
R-7.5 continuous insulation installed over an existing slab is deemed to be equivalent to the required perimeter
slab insulation when applied to existing slabs complying with Section R503.1.1. If foam plastic is used, it shall meet
the requirements for thermal barriers protecting foam plastics.
g For log structures developed in compliance with Standard ICC 400, log walls shall meet the requirements for
climate zone 5 of ICC 400.
h
Int. (intermediate framing) denotes framing and insulation as described in Section A103.2.2 including standard
framing 16 inches on center, 78% of the wall cavity insulated and headers insulated with a minimum of R-10
insulation.
All Climate Zones (Table R402.1.1)
R-Value a U-Factor a
Fenestration U-Factor b n/a 0.30
Skylight U-Factor b n/a 0.50
Glazed Fenestration SHGC b,e
Provide all information from the following tables as building permit drawings: Table R402.1 - Insulation and
Fenestration Requirements by Component, Table R406.2 - Fuel Normalization Credits and 406.3 - Energy Credits.
Multifamily (effective February 1, 2021)
These requirements apply to Group R-2 buildings three stories or less in height above grade plane.
Other Group R-2 buildings must comply with the commercial energy code.
n/a n/a
Ceiling e 49 0.026
W ood Frame W all g,h 21 int 0.056
Floor 30 0.029
Below Grade W all c,h 10/15/21 int + TB 0.042
Slab d,f R-Value & Depth 10, 2 ft n/a
09/28/2021
Tahoma Terra Apartments - Building C
14301 TAHOMA BLVD SE YELM, WA 98597
Bill Bowdish - Ross Deckman & Associates, Inc
bill@rdarchitect.com or 253-840-9405
Version 1.0
2018 Washington State Energy Code – Residential
Prescriptive Energy Code Compliance for All Climate Zones in Washington
Multifamily R2 Dw elling Unit: 4.5 credits
Before selecting your credits on this Summary table, review the details in Table 406.3 (Multifamily), on page 3.
Summary (Table R406.2)
Heating
Options Fuel Normalization Descriptions Credits - select ONE
heating option User Notes
1 Combustion heating minimum NAECAb 0.0
3 Electric resistance heat only - furnace or zonal -1.0
4 DHP with zonal electric resistance per option 3.4 na
5 All other heating systems -0.5
Energy
Options Energy Credit Option Descriptions
Credits - select ONE
energy option from each
category d
1.1 Efficient Building Envelope 0.5
1.2 Efficient Building Envelope 1.0
1.4 Efficient Building Envelope 1.0
1.5 Efficient Building Envelope 1.5
1.6 Efficient Building Envelope 2.0
1.7 Efficient Building Envelope 0.5
2.1 Air Leakage Control and Efficient Ventilation 1.0
2.2 Air Leakage Control and Efficient Ventilation 1.5
2.3 Air Leakage Control and Efficient Ventilation 2.0
2.4 Air Leakage Control and Efficient Ventilation 2.5
3.3a High Efficiency HVAC 1.0
3.4 High Efficiency HVAC 2.0
3.6a High Efficiency HVAC 3.0
4.1 High Efficiency HVAC Distribution System 0.5
5.1d Efficient Water Heating 0.5
5.2 Efficient Water Heating 0.5
5.3 Efficient Water Heating 1.0
5.4 Efficient Water Heating 2.0
5.5 Efficient Water Heating 2.5
5.6 Efficient Water Heating 3.0
6. 1e Renewable Electric Energy (3 credits max) 1.0
7.1 Appliance Package 1.5
Total Credits
a. An alternative heating source sized at a maximum of 0.5 W/sf (equivalent) of heated floor area or 500 W,
whichever is bigger, may be installed in the dwelling unit.
b. Equipment listed in Table C403.3.2(4) or C403.3.2(5)
with options 5.2 through 5.6. See Table 406.3.
e. 1.0 credit for each 1,200 kWh of electrical generation provided annually, up to 3 credits max. See Table R406.2 for
full requirements and complete option descriptions.
Prescriptive Path – Multifamily 2018 Washington State Energy Code-R 2
d. You cannot select more than one option from any category EXCEPT in category 5. Option 5.1 may be combined
3.1a High Efficiency HVAC 1.0
2 Heat pumpc 1.0
Each dwelling unit in a residential building shall comply with sufficient options from Table R406.2 (fuel
normalization credits) and Table 406.3 (energy credits) so as to achieve the following minimum number of credits:
Multifamily (effective February 1, 2021)
c. Equipment listed in Table C403.3.2(1) or C403.3.2(2)
l
l
l
Clear Form
na = 0 per WSEC official
Please print only pages 1 and 2 of this worksheet for submission to your building official.
Calculate Total4.5
f. Use the single radiobutton in the upper right of the second column to deselect radiobuttons in that group.