Home›Knowledge›NEC 220.83 — Existing Dwelling Optional Calculation
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NEC 220.83 — Existing Dwelling Optional Calculation

Updated May 22, 2026
Alternative load-calc method for existing single dwelling units: first 8 kVA of all loads at 100%, remainder at 40%, plus A/C at 100%.

Used when sizing or upsizing service to an existing dwelling without doing the full 220.42-44 calc. Implementation: src/lib/mep-load-calc.ts calculateElectricalLoad() default method for dwelling types.

TAGS
NEC220.83existing-dwellingservice-upgradeoptional-method
DETAILS
book
NEC 2023
section
220.83
mep calc workflow
q-panel-schedule
SOURCES
🔗https://codes.iccsafe.org/content/NFPA702023/article-220
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