Texas Electrical Code PrepWhat changed in the 2026 edition

Checked against primary sources 2026-08-24

The dwelling figure that sizes a service is 2 volt-amperes per square foot now

Load calculations left Chapter 2 and landed in Chapter 1 as Article 120. One constant inside them changed value on the way, and a second constant was created so that the first one would stop doing two jobs.

On this page
  1. Two unit loads where the 2023 book had one
  2. Non-dwelling occupancies, and the note that is not there any more
  3. Where the general rules moved inside the article
  4. The optional calculations, and which dwelling each one is written for
  5. Parts that arrived from other chapters
  6. What to do with a calculation sheet built on the old book
  7. What this page cites

Two unit loads where the 2023 book had one

A dwelling now takes its general lighting and general-use receptacle load from one of two figures, and which one depends on what you are sizing.

In the 2023 book there was a single figure, at 220.41, and it was 3. So the number that sizes the service came down by a third, and the number that decides how many branch circuits a dwelling needs was written into a section of its own at 120.13 so that the circuit count would not fall along with it.

On a 5,000 square foot house that one line moves from 15,000 volt-amperes to 10,000, which is roughly 62 amperes down to 42 at 240 volts before anything else in the calculation is touched. The rest of the calculation is unchanged, so the whole of the difference lands on the service.

This is the change most worth marking in your own book, because both figures are real, both live in Article 120, and using the service figure to count branch circuits or the branch-circuit figure to size a service produces an answer that looks reasonable in either direction.

Non-dwelling occupancies, and the note that is not there any more

Unit loads for occupancies other than dwellings come from Table 120.42(A), General Lighting Loads by Non-Dwelling Occupancy. The values in it were not altered for this edition.

What was altered is the explanatory note that used to sit under it in the 2023 book, saying the 125 percent increase for continuous operation was already built into the printed values. That note is gone from the 2026 table and nothing replaced it.

Mark Ode raised this in Electrical Contractor Magazine as a live risk of double counting, because a reader who has never seen the old note has no reason to suspect the values already carry the increase. Read the table in your own book and check what your calculation software is doing with it.

Where the general rules moved inside the article

Article 120 opens with a short Part I that now carries rules the 2023 book kept further back, which changes where you look for them rather than what they say.

Floor area is worth a second look even though the wording did not change. NEC 120.5(C) takes the area from the outside dimensions of the building, and for a dwelling it excludes a detached garage, an open porch, and unfinished space that is not adaptable for future use as a habitable room. The test on an unfinished basement is adaptability, not what is in there today.

The optional calculations, and which dwelling each one is written for

Part IV holds several optional methods and they are not interchangeable. Each opens with a sentence describing the installation it applies to, and that sentence is the whole of the eligibility test.

All of them run the general lighting and general-use receptacle load at 2 volt-amperes per square foot, so the change described at the top of this page reaches the optional methods as well as the standard one.

NEC 120.83 was reworked for this edition. The panel moved the language about clothes dryers so that a load already counted through a default branch-circuit value does not get counted a second time at its nameplate, and it extended that principle past dryers to the other equipment in the list. Electric vehicle supply equipment on an individual branch circuit is named in that list.

Parts that arrived from other chapters

Article 120 absorbed calculation material that used to live with the occupancy it belonged to. Recreational vehicle park calculations and mobile and manufactured home park calculations are now Parts VIII and IX of Article 120.

That is a real change of habit for anyone who has spent years turning to Article 551 or Article 550 for the park demand. The installation rules are still there. The arithmetic is not.

Farm load calculations and health care facility calculations sit in Article 120 as well, in their own parts, which is where the equivalent material was before the move.

What to do with a calculation sheet built on the old book

The sequence still works. Nothing about the order of a dwelling calculation was rewritten, and a worked example from a 2023 course still teaches it correctly.

Two things on that sheet are now wrong. Every 220 citation is pointing at a vacant article number, and the general lighting constant is a single value where the book now has two.

Fix the constant first. A wrong citation costs somebody a minute of hunting. A wrong constant propagates through every line below it and produces a service size that nobody catches, because the number it produces is plausible.

What this page cites

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