Which NEC method does this use?

It uses the standard calculation method of NEC Article 220 Part III for dwellings. General lighting is 3 VA per square foot plus the small-appliance and laundry circuits, with a demand factor that takes the first 3000 VA at 100 percent and the remainder at 35 percent.

How is the general lighting load found?

Multiply the living area in square feet by 3 VA, then add two small-appliance circuits at 1500 VA each and one laundry circuit at 1500 VA. This subtotal gets the 100 percent then 35 percent demand factor before being added to the appliance loads.

Why take the larger of heating or air-conditioning?

NEC 220.60 allows omitting the smaller of two non-coincident loads because heating and cooling do not run at the same time. The worksheet includes only the larger of the two, which avoids oversizing the service for loads that never coincide.

Does this size the service conductors?

It gives the calculated service amperes, which is the basis for selecting the service rating. You still size the conductors from the ampacity tables with temperature and termination corrections, and round up to a standard service such as 100, 150, or 200 amps.

Is this acceptable for a permit?

It produces the standard load summary that most building departments expect, but every AHJ has its own form and may require the optional method or extra detail. Use the figures as the calculation basis and transfer them onto the jurisdiction's official worksheet.

What is the Electrical Permit Load Summary Generator?

Takes dwelling square footage, service voltage, and panel ampacity to produce a NEC Article 220 standard-method dwelling load summary, including general lighting, small-appliance and laundry circuits, fixed appliances, and the larger of heating or air-conditioning, with the resulting service amps. Runs entirely in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Electrical Permit Load Summary Generator

Name: Electrical Permit Load Summary Generator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Most building departments want a load summary before they issue a residential electrical permit. This generator follows the NEC Article 220 standard calculation method: it sums general lighting, small-appliance, laundry, and fixed appliance loads, applies the demand factors, takes the larger of heating or cooling, and reports the calculated service amperes against your panel rating.

How it works

The standard dwelling method assembles the loads and applies a demand factor to the general portion:

general lighting  = area_ft² × 3 VA
small appliance   = 2 circuits × 1500 VA = 3000 VA
laundry           = 1 circuit × 1500 VA
general subtotal  = lighting + small appl + laundry
demand applied    = 3000 VA at 100% + remainder at 35%
fixed appliances  = range + dryer + water heater + other (nameplate VA)
hvac              = larger of heating or A/C (220.60, non-coincident)
total VA          = demand applied + fixed appliances + hvac
service amps      = total VA / service voltage

The first 3000 VA of the general subtotal is counted in full, and everything above that is taken at 35 percent, which reflects that not all lighting and receptacle load runs at once.

Worked example

A 2000 square foot dwelling has 6000 VA of general lighting, plus 3000 VA small-appliance and 1500 VA laundry, for a 10,500 VA general subtotal. Applying the demand factor gives 3000 + (7500 × 0.35) = 5625 VA. Add an 8000 VA range, a 5000 VA dryer, a 4500 VA water heater, and a 6000 VA air conditioner (larger than the heat), for 29,125 VA total. At 240 volts that is about 121 amps, so a 150 amp service is the next standard size.

Understanding the demand factor

The 100%/35% split on the general subtotal is not arbitrary. NEC 220.42 codifies the observation that a home’s lighting and receptacle circuits are never all loaded simultaneously. Code requires the first 3000 VA in full because some base load is always present, but the rest is discounted to reflect diversity of use.

Fixed appliances like ranges and water heaters do not receive this discount because they are single loads that can run at or near nameplate. That is why a 10 kW electric range counts at full VA while thousands of square feet of lighting get derated.

Common errors on permit submissions

Forgetting the two small-appliance circuits — NEC 210.11(C)(1) requires at least two 20 A circuits for kitchen receptacles; their 3000 VA must appear in the general subtotal regardless of what is actually plugged in.
Using connected load instead of nameplate — enter the nameplate rating of the appliance, not an estimate of typical running load.
Omitting the larger HVAC load — if both electric heat and central air are present, NEC 220.60 permits using only the larger non-coincident load, but you must still include it. Omitting HVAC entirely undersizes the service.
Wrong voltage basis — single-phase 240 V services divide total VA by 240; confirm your service voltage before reading the calculated amps.

After the generator

Transfer the figures onto your AHJ’s official permit worksheet. Some jurisdictions use the optional calculation method under NEC 220.82 for new construction, which can result in a smaller service. The standard method used here is always conservative and always accepted. Keep the completed load summary with the permit set for inspection.