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Duplex Home: Load Calculation
Code editionNEC 2023NEC 2026 New
NEC 2026: load calculations are in Article 120 (formerly Article 220). Use it only where the 2026 NEC is adopted.
Duplex Home Load Calculation
Unit __number__ Details
Dwelling Unit
2 if both dwelling units are identical; otherwise 1 here and add a second unit type.
Per dwelling unit, from outside dimensions (NEC 120.5(C)).
1,500 VA each, minimum 2 (120.82(B)(2)).
1,500 VA each, minimum 1.
Fixed Appliances
Nameplate VA. Enter 0 if not installed.
Other Appliances
Pool pump, spa, sauna, etc. Nameplate VA.
Cooking, Laundry & Water Heating
Nameplate VA (kW × 1000). Enter 0 if not electric.
Do not use Table 120.55 values.
California50A, 240/208V labeled circuit for future range (2025 Energy Code).
California30A, 240/208V labeled circuit for future dryer (2025 Energy Code).
California30A, 240/208V labeled circuit for future water heater (2025 Energy Code).
Heating & Cooling
The larger of the heating and cooling loads is used (120.82(C)).
Condensing unit or heat pump. 0 if none.
Fan motor only (excludes supplemental heat).
Total nameplate kW.
4 or more: 40%. Fewer: 65%.
EV Charging
Counted at 100% (no demand factor).
Per dwelling unit. Use charger nameplate if installed. 0 if none.