New 2026 NEC Optional Calculation 120.83

[Elecbeej02]

Hello all! Hoping to get some clarification and opinion on the following regarding the residential optional calculation for existing dwellings 120.83

As I understand any heating and cooling load is to be calculated per 120.82(C) as also shown in the annex D examples. These loads are not included in the general load deration. Is this correct?

I understand that new EVSE can be added separately at 80% but how are existing EVSE loads to be calculated? 120.82(D) clearly states to add separately at 100% however EVSE is specifically listed in 120.83(3) along with the other general loads that are acceptable for deration. Which should be used?

Finally, 120.83 Table says “other new loads at 50%” here is my question. If my new load is a range, oven, water heater or dryer, because those appliances are specifically listed in 120.83(3) and included in the general derated loads are they calculated there, or am I overthinking and it’s as simple as if it is not a new EVSE, electric resistance space heating or heating and air conditioning it is added at 50%?

Thanks in advance

 

[wwhitney]

When reading 120.83, ignore everything in 120.82. So we have:

2026 120.82: General loads at 100% for the first 8 kVA, 40% for the rest, plus HVAC load at various specified factors, plus 100% of the EVSE load.

2026 120.83: All existing loads at 100% for the first 8 kVA, 40% for the rest (this includes EVSE and HVAC loads, although you get to omit the smaller of the heating or cooling), plus new EVSE and electric resistance space heating at 80%, plus all other new loads at 50%.

Cheers, Wayne