The short answer: under the 2026 National Electrical Code, use 2 VA/ft² to calculate the dwelling general-lighting and general-use-receptacle component of a feeder or service load. Use 3 VA/ft² separately to determine the minimum capacity—and therefore the minimum count—of the dwelling’s general-lighting and general-use-receptacle branch circuits. One square-footage input now feeds two calculations; neither result replaces the other.
This split applies only when the 2026 NEC is the project’s adopted code. An authority having jurisdiction (AHJ) may still enforce an earlier edition or a local amendment. Put the edition, jurisdiction, floor-area basis, and both formulas on the calculation sheet so a reviewer can see which rule produced each number.
Last checked: August 18, 2026, Pacific Time. The controlling model-code references are 2026 NFPA 70 Sections 120.13 and 120.41. Local adoption and amendments still control the project.
What changed in the 2026 NEC?
The 2026 edition reorganized load calculations from Article 220 into Article 120. More importantly for dwellings, Section 120.41 reduced the minimum unit load for general lighting and general-use receptacles from 3 VA/ft² to 2 VA/ft². The standard and optional dwelling methods use that lower value in the feeder and service calculation.
The old 3 VA/ft² value did not vanish. Section 120.13 uses it to determine the minimum number of 15- or 20-ampere, 2-wire general-lighting and general-use-receptacle branch circuits. This preserves branch-circuit capacity while allowing the feeder and service calculation to reflect the lower diversified load expected from modern lighting and plug loads.
The NFPA Code-Making Panel 2 first-draft record documents the technical history behind the lower dwelling unit load. A separate April 2026 City of Austin code-change analysis summarizes the final practical boundary in plain terms: the dwelling general lighting and receptacle load falls to 2 VA/ft², while branch circuits are still calculated at 3 VA/ft².
That history is useful context, but the enforceable question is simpler: which edition and amendments has the project’s AHJ adopted?
Start with one controlled floor-area input
Both paths begin with the same included dwelling floor area. Section 120.5(C) controls how that area is calculated and which spaces are excluded. Do not let an architectural gross-area label, conditioned-area number, tax-record area, or energy-model area flow into the electrical worksheet without checking that it matches the NEC definition.
Record four things beside the input:
- the source drawing and revision;
- the included floor area in square feet;
- excluded spaces and the section that permits each exclusion;
- the person and date responsible for the measurement.
If the area changes, both calculations must update. That is why a worksheet should keep a single controlled area cell but two separate formula cells.
Worked example: a 2,400 ft² dwelling
Assume the project’s AHJ has adopted the 2026 NEC without an amendment to these sections. The included floor area under Section 120.5(C) is 2,400 ft². All general-lighting branch circuits in this example are 120-volt, 2-wire circuits of one rating.
Path 1: feeder and service load component
2,400 ft² × 2 VA/ft² = 4,800 VA
The 4,800 VA result is not the service size. It is the floor-area component of the dwelling load calculation. A complete calculation still accounts for the required small-appliance and laundry loads, appliances, cooking equipment, dryers, heating and air conditioning, motors, EV supply equipment, and other applicable loads. It then applies the standard or optional method and the relevant demand factors.
Do not convert 4,800 VA to 40 amperes at 120 volts and label the dwelling “40 A.” A dwelling feeder or service is a multi-load, usually 120/240-volt system calculation. This single component cannot size it by itself.
Path 2: minimum branch-circuit capacity
2,400 ft² × 3 VA/ft² = 7,200 VA 7,200 VA ÷ 120 V = 60 A of minimum branch-circuit capacity
If all the applicable circuits are 20 A, divide 60 A by 20 A: the minimum is three circuits. If all are 15 A, divide 60 A by 15 A: the minimum is four circuits. When the quotient is not a whole number, round up because a fraction of a branch circuit cannot satisfy the minimum.
This arithmetic does not decide how the circuits are laid out. Required small-appliance, laundry, bathroom, garage, and other circuits remain governed by their own rules. AFCI, GFCI, conductor ampacity, voltage drop, load distribution, and the actual connected equipment can require a design beyond the numerical minimum.
| Question | 2026 NEC input | 2,400 ft² result | Where the result goes |
|---|---|---|---|
| What general lighting and receptacle load enters the feeder or service calculation? | 2 VA/ft² | 4,800 VA | Into the complete dwelling load method |
| What minimum general-lighting branch-circuit capacity is required? | 3 VA/ft² | 7,200 VA, or 60 A at 120 V | Into the 15 A or 20 A circuit-count calculation |
A review procedure that prevents the mix-up
- Name the code of record. Write “2026 NFPA 70” only after confirming the adopted edition and local amendments.
- Lock the floor-area basis. Cite the plan revision and Section 120.5(C) treatment of exclusions.
- Calculate the 2 VA path. Label the result “general lighting and general-use receptacle component—feeder/service,” not “total service.”
- Calculate the 3 VA path. Convert the VA result to minimum circuit capacity using the actual circuit voltage and rating, then round the circuit count up.
- Finish each downstream job independently. Complete the feeder/service load method on one path and the branch-circuit schedule on the other.
- Cross-check the drawings. The panel schedule must contain at least the calculated general-lighting circuit capacity, while the one-line and load summary must carry the completed feeder/service result.
The best spreadsheet design makes an accidental substitution obvious. Give the two output cells different labels and colors, prohibit manual overwrite, and include the cited section beside each formula. A single unlabeled “VA per square foot” field is a latent review error.
Common failure modes
- Using 2 VA/ft² to reduce the branch-circuit count. Section 120.13 keeps the separate 3 VA/ft² branch-circuit calculation.
- Using 3 VA/ft² everywhere on a 2026 NEC project. That overstates the floor-area component of the feeder/service load and hides the edition change.
- Applying 2026 rules in a 2023 jurisdiction. A newer model code is not automatically enforceable.
- Calling 2 VA/ft² measured consumption. It is a code unit load, not an energy audit, utility demand reading, or prediction of a specific household.
- Stopping after the floor-area component. The service and feeder calculation has many additional loads and demand rules.
- Treating the circuit-count minimum as a room-by-room design. The minimum capacity does not replace branch-circuit placement, protection, load balancing, or dedicated-circuit requirements.
What belongs on the drawing set?
The load summary should show the adopted code edition, included floor area, 2 VA/ft² formula, chosen dwelling calculation method, downstream additions, demand factors, and final feeder/service result. The panel schedule or branch-circuit calculation should independently show the 3 VA/ft² formula, nominal voltage, circuit rating, quotient, and rounded-up circuit count.
If the project team needs to review where the completed load lands, use ChatDiagram’s single-line diagram generator to draft the service, feeders, panels, and loads. Keep the calculation worksheet as the source of truth; the generated one-line is a coordination surface, not an AHJ approval or an engineered calculation.
The durable rule is simple enough to print at the top of the worksheet: 2 VA/ft² sizes one component of the feeder/service load; 3 VA/ft² checks minimum general-lighting branch-circuit capacity. Same area, different decisions.