WSU_C32021_CypressWSU Code Compliance Calculator, WSEC 2021
Project Information Messages / Comments *RESULT=PASS
Medium Dwelling Unit
LGI Homes Plan Cypress Note: Review required for custom entries: - Wall (above grade)
UA Reduction = 24.26, Proposed UA is better than baseline by 10.3%
Contact Information
Window area is 11% of floor area
-
Whole House Mechanical Ventilation Airflow Rate: 50 CFM with Run Time Percent of 100%, Balanced, Distributed
Maximum allowable total measured duct leakage: 130 CFM25
ANALYSIS SET UP
What code compliance pathway are you using?
Project Building Type?
Occupancy Type?
Code Version?
Classification:Medium Dwelling Unit -- 1623 sq. ft.
Baseline Description: Code Baseline - Maximum baseline window area is 15% of floor area.
About Your Selection:No exempt window or door areas
-
RESULTS - Comparison of Baseline and Proposed Design **
Component Performance, R occupancies
U *Area UA Area UA
Doors U =0.300 42 12.5 42 12.5
Overhead Glazing U =0.500 0 0.0 0 0.0
Vertical Glazing U =0.300 180 53.9 180 44.9
Flat/Vaulted Ceilings U =0.024 1,034 24.8 1,034 25.9
Wall (above grade) U =0.056 2,030 113.7 2,030 101.5
Floors over Crawlspace U =0.029 1,034 30.0 1,034 25.9
Slab on Grade F =0.540 0 0.0 0 0.0
Below Grade Wall U =N/A 0 0 0.0
Below Grade Slab F =N/A 0 0 0.0
* Values from Table R402.1.2 (Oct 2023)
Baseline UA Total 234.9 Proposed UA Total 210.6
Required Credits 8.0 Proposed Credits 8.0 from Tables 406.2 and 406.3
UA Percent Reduction 10%
UA Reduction 24.3
** Results assume your inputs are complete and correct. Results do not constitute an approval. Analysis should be reviewed by your AHJ.
Total Credits
(406.2 & 406.3)
8.0
* Results assume your inputs are complete and correct. Results do not constitute an approval. Analysis should be reviewed by your AHJ.
Air source ducted Heat Pump w/ Min HSPF2 of 10 (HSPF of 11). If htg
design temp is 23F or below,a cold climate variable capacity heat pump
is required.
Ducts/distribution system in conditioned space per R403.3.2 Electric
resistance, hydronic, ductless and gas fired systems < 80% AFUE
systems not permitted
1.0
0.5
Table R406.2 Energy Equalization Credits
3.0Variable Refrigerant Heat Pump or Air-to-
Water Heat Pump
Select Options
Not Selected -
Per Section R402.4.1.2 / 2.0 ACH50 / For R-2, 0.25 cfm per ft2 at 50 Pa.
/ HRV with min SHR eff of 0.65 per IRC Section M1505.3 or IMC
Section 403.8
Table R406.3 Energy Credits
Option No.
2 Air Leakage Control and Efficient Ventilation
Efficient Building Envelope
3.1 -3.10
Energy Credits (406.3)
High Efficiency HVAC Distribution System4
System No.
4
Option 2.1
Fuel Normalization
Credits (406.2)
1
Option 3.6
5.0
Full Description
For heating system using a heat pump that meets federal standards for the equipment
listed in Table C403.3.2(2) or Table C403.3.2(9) OR Air to Water heat pump units that
are configured to provide both heating and cooling and are rated in accordance with
AHRI 550/590
High Efficiency HVAC
Option 4.1
Energy Credits
3.11 Not SelectedHigh Efficiency HVAC: Smart Thermostat 0.0 -
0.250
0.025
0.050
0.025
Proposed Design
Total UA Alternative, Whole Building Trade Off Analysis
U
Baseline
New Construction
R3 Single family dwellings and townhouses
WSEC 2021
0.300
0.0
Brief Description of Selected Options*
1.0
Category
Select System Type
WSU_C32021_Cypress.xlsm 5/19/2025 1
WSU Code Compliance Calculator, WSEC 2021
Renewable Electric Energy kWh
Energy Credits
*Refer to WSEC 2015 Table R406.2 for complete option descriptions and requirements
0.0
Electric heat pump water heater meeting NEEA Tier 3.
Compact Hot Water Distribution System Max volume between heat
source and fixture is 16 Oz per section R403.5.2, on demand circ. Pump
may be required.
0.0
5.0
7 Appliance Package
Efficient Water Heating: Drain Heat Recovery
Efficient Water Heating
Efficient Water Heating: Compact Hot Water Distribution
5.1
5.3-5.8
5.2
6
2.0
Option 5.6
Option 5.2 0.5
0.0
Not Selected
WSU_C32021_Cypress.xlsm 5/19/2025 2
WSU Code Compliance Calculator, WSEC 2021
THERMAL ENVELOPE DETAILS - Proposed Design
Conditioned Floor Area, Proposed Design 1,623 sq. ft
Classification Medium Dwelling Unit
Exterior Doors
Plan Component Door
ID Description Ref. U Qt. Feet
Inch Feet Inch Area UA
Code Baseline, U=0.30 - 0.30 1 3
0 8 0 24 7.2
Code Baseline, U=0.30 - 0.30 1 2
8 6 8 18 5.3
0 0.0
0 0.0
0 0.0
0 0.0
0 0.0
0 0.0
0 0.0
0 0.0
Sum of Area and UA 42 12.5
0 0
Exterior Doors Area Weighted U 0.300
Overhead Glazing
Plan Component Glazing
ID Description U Feet
Inch Feet Inch
-
-
-
-
-
0.0 0
0 0
Overhead Glazing Area Weighted U
Vertical Glazing Schedule Rows to Show 5
Plan Component Glazing
ID Description U Feet
Inch Feet Inch
1 U=0.25 (2021 1.2; 2018 1.4)Table 406.2 / 406.3 0.25 1 3
0 4 6 13.5 3.38
2 U=0.25 (2021 1.2; 2018 1.4)Table 406.2 / 406.3 0.25 1 6
0 6 10 41.0 10.25
3 U=0.25 (2021 1.2; 2018 1.4)Table 406.2 / 406.3 0.25 3 5
0 5 0 75.0 18.75
4 U=0.25 (2021 1.2; 2018 1.4)Table 406.2 / 406.3 0.25 5 2
0 2 0 20.0 5.00
5 U=0.25 (2021 1.2; 2018 1.4)Table 406.2 / 406.3 0.25 2 3
0 5 0 30.0 7.50
Sum of Area and UA 179.5 44.9
0
Vertical Glazing Area Weighted U 0.250
Vertical Glazing and Doors Area Weighted U 0.259
Flat/Vaulted Ceilings
Plan Component Attic
ID Description U
R60 blown Attic STD baffled 10-7 0.025 1,034 25.9
1,034 25.9
0
Walls (Above Grade)
Plan Component Wall
ID Description Ref. U UA
R23 BIBS 2x6W Custom 0.050 2,030 102 Refer to WSEC R402.1.5 U-factor Reference and Calculations
2,030 102
1
Width
Ref.
Ref.
Height
Notes
Height
Area
Width
Qt.
Sum of Area and UA
Qt. UAArea
HeightWidth
Sum of Area and UA
Net Area
Sum of Area and UA
Ref.
UA
Area UA
WSU_C32021_Cypress.xlsm 5/19/2025 3
WSU Code Compliance Calculator, WSEC 2021
Floor (over crawl or exterior)
Plan Component Floor UA
ID Description Ref. U
R38 vented Joist (2021 1.2, 1,3; 2018 1.3-1.5)10-3 0.025 1,034 26
1,034 26
0
Slab on Grade (less than 2 feet below grade)
Plan Component Slab
ID Description Ref. F FP
0 0
0
Below Grade Walls and Slabs
Plan Component Slab Wall Wall Wall Slab
ID Description Depth Ref. U Area UA UA
Sum of Area, Length and UA 0 0.0 0 0
0
Links to Download Forms, Checklists and Other Resources
Compliance Certificate Instructions
Insulation Certificate for Residential New Construction
Duct Testing Affadavits
Existing Construction
New Construction
Prescriptive Checklist for 2018 WSEC
Alterations (Remodel) Worksheet
EER SEER2 COP HSPF2 Converter https://www.adicotengineering.com/eer-seer2-cop-hspf2-kwton-converter
Ventilation Requirements
Conditioned Floor Area 1,623 sq. ft.
Number of Bedrooms 3
Run-Time Percent in Each 4-Hour Segment 100%
Is the system Balanced?Verify system meets definition of 'Balanced Whole-House Ventilation'
Is the system Distributed?Verify system meets definition of 'Distributed Whole-House Ventilation'
Ventilation Code Section IRC, Chapter 15
Whole House Mechanical Ventilation Airflow Rate 50 CFM
HVAC Thermal Distribution System Download RS-33 (2018)
Is this a hydronic heating system?
Location of Ducts
Location of Air Handler
Is Duct Testing Required? Yes
Maximum Duct Leakage:
Maximum total measured duct leakage per square foot 0.08 CFM25 per sq. ft.
Maximum allowable total measured duct leakage 130 CFM25
A maximum of 10 feet of return ducts and 5 feet of supply ducts are allowed to be located outside of the building thermal envelope, if insulated and sealed per R403.3.7.
Heating System Sizing - Proposed Design Try Out BetterBuiltNW's HVAC Sizing Tool:
Nearest Weather Station
Indoor Design Temperature 70 F
Outdoor Design Temperature 24 F
Design Temperature Difference (∆T)46 F
Conditioned Floor Area, Proposed Design 1,623 ft2
Conditioned Volume 15,336 ft3 0.00
Leave blank to use default of 8.5 ft. ceiling height
HVAC System Type
Location of HVAC Distribution System Conditioned Space
http://www.energy.wsu.edu/Documents/Duct%20Testing%20Standards%20_2018%20WSEC.pdf
Conditioned Space
https://betterbuiltnw.com/resources/hvac-sizing-tool
Link
Prescriptive Checklist
Affidavit, Existing
Affidavit, New
Worksheet
No
Sum of Perimeter and FP
Slab
Perim
Compliance Certificate
Insulation Certificate
Sum of Area and UA
Distributed
Balanced
Slab Slab
Perim
Seattle: Sea-Tac AP
Conditioned Space
Area
F
Heat Pump
WSU_C32021_Cypress.xlsm 5/19/2025 4
WSU Code Compliance Calculator, WSEC 2021
Sum of UA 211
Envelope Heat Load 9,688 Btu / Hour
Sum of UA X ∆T
Air Leakage Heat Load 7,619 Btu / Hour
((Volume X 0.6) X ∆T) X .018))
Building Design Heat Load 17,307 Btu / Hour
Air Leakage + Envelope Heat Loss
Building and Duct Heat Load 17,307 Btu / Hour
For ducts located in unconditioned space: Sum of Building Heat Loss X 1.1
For ducts located in conditioned space or ductless: Sum of Building Heat Loss X 1
Maximum Heat Equipment Output 21,634 Btu / Hour
Building and Duct Heat Loss X 1.25 for heat pumps 6.3 kW
Building and Duct Heat Loss X 1.40 for all other systems
WSU_C32021_Cypress.xlsm 5/19/2025 5