Eight lessons
120.1–120.7, calculation framework: justify noncoincident loads and power control system assumptions. Continuous loads do not automatically get 125 percent in Article 120; conductor and protection sizing remains a separate check.
120.10–120.16, branch-circuit loads: assign loads by occupancy and equipment type. Use lighting input ratings, not lamp watts alone. Spare breaker space is not spare electrical capacity.
120.40–120.47, feeder and service loads: apply demand only to qualifying loads. Feeder and service lighting demand factors do not reduce the number of required branch circuits.
120.50–120.61, motors, HVAC and equipment: motors, heat, appliances and EV charging follow different rules. Check neutral loading, not just phase loading.
120.80–120.85, dwelling and multifamily options: confirm eligibility. Do not apply one blanket factor to general loads, heating and cooling, EV charging and shared building loads.
120.86–120.88, schools, existing loads and restaurants: use the applicable method. Measured demand requires qualifying records and operating conditions, not a single meter reading.
120.100–120.120, farms, health care and marinas: specialty demand factors apply to defined loads. The facility type does not justify reducing every load.
120.130–120.141, RV parks, mobile and manufactured homes: verify site type, supply configuration and unit count. Calculate shared amenities separately.
Field and plan-review takeaway
Before accepting a calculation, check the method and eligibility, current equipment ratings and operating sequences, the table and load portion receiving each demand factor, and existing capacity and proposed additions. Reconcile the calculation with one-lines, panel schedules and mechanical and equipment schedules.
A smaller calculated load is useful only when the reduction is defensible. Next: NEC 2026 Article 130 Energy Management Systems: Series Kickoff.
Questions to settle before design
Which calculation method applies, and is the project eligible for it?
Which loads qualify for demand factors, and which do not?
Is there measured demand data, and does it meet the qualifying conditions?
MasterBuild field checklist
Reconcile the calculation with panel schedules, the one-line and equipment nameplates.
Confirm the edition: a Florida permit today cites Article 220 of NEC 2020.
Check existing capacity before adding EV charging or new HVAC loads.
MasterBuild recommendation: process steps for design and site review, not code text.
Where MasterBuild helps
Load calculations prepared and reviewed by the PE, or send your project background. The fee is quoted in writing before work starts.
Code basis and applicability
Study edition: NEC 2026 (NFPA 70). Florida enforces NEC 2020 under the 2023 Florida Building Code (8th Edition). The 9th Edition (published; state adoption pending) adopts NEC 2023 for permit applications on or after 12/31/2026. Section numbers and some rules differ between editions. Verify the edition that governs your permit. NEC 2020 and NEC 2023, which Florida enforces, place these load calculations in Article 220, not Article 120. Educational reference to NEC 2026 Article 120. Check the complete NFPA 70 text, the locally adopted edition and amendments, the authority having jurisdiction, and the selected equipment instructions before project use.