Checked against primary sources 2026-09-05

SP-SFD

NC Residential Dwelling Electrical Exam: SP-SFD Format

Residential Dwelling is the special restricted classification most house wirers ask about. Its paper is 40 questions in three hours, it uses the same minimum grade of 70 as every other examination this Board runs, and it is one of the two special restricted classifications allowed to carry NFPA 72.

Test yourself: thirty free questions, timed

The classification

The Board lists Residential Dwelling, coded SP-SFD, as one of seven special restricted classifications. The annual license fee is $100, the same as every special restricted classification.

The scope of the license is set in Section .0800 of Title 21 NCAC 18B. We are not going to paraphrase that boundary into something that sounds simple, because the difference between what SP-SFD permits and what a Limited license permits is exactly where people get into trouble.

Read the rule, and if a job sits near the edge of it, ask the Board before you sign for the work.

The paper

Forty multiple choice questions, a maximum of three hours. A minimum grade of 70 out of a possible score of 100.

Forty questions over three hours is the most generous clock the Board offers, at four and a half minutes a question. On an open book paper that is enough time to look up almost everything, which changes what you should practice: knowing where a rule lives matters more than remembering it.

The same 40 question, three hour format covers SP-SFD, SP-PH, SP-ES, SP-EL and SP-WP in the handbook.

The books you may carry

The 2020 National Electrical Code, required, as on every examination.

The 2013 edition of NFPA 72 is allowed for this classification. Only Limited, Intermediate, Unlimited, SP-SFD and SP-FA/LV get it, so SP-SFD is on the shorter list.

Those two books are the whole of what you carry. The licensing law in Chapter 87 Article 4, the Board's rules in 21 NCAC 18B and the NASCLA Contractors' Guide, North Carolina Electrical Edition, are closed book study references, so their marks come out of preparation.

Lighting and Power Plans are printed in the handbook for Limited, Intermediate and Unlimited only, so they do not appear on this paper.

Who can sit for it

Minimum age 18, a duly filed application, two written character statements.

At least 3,000 hours of experience, of which at least 2,000 hours must be primary experience. SP-SFD does not carry the extra employment verification the trade specific special restricted classifications require.

Residential work counts as primary experience when it is direct installation of wiring and equipment governed by the National Electrical Code. Apprentices in approved North Carolina programs count at 100 percent as secondary experience, which is a different bucket. Read the hours page before you total anything.

Money, booking and the wait

$125 for the application and examination, non-refundable. $100 a year for the license. $25 for an examination review.

PSI books the seat once the Board approves you, and the approval lasts 90 days. Two days notice keeps a cancelled appointment from costing the fee.

After a failure, three months in the same classification. The Board's examinations page prints the same wait as 90 days.

How to prepare for it

The Board publishes no prep class and endorses none. It tells candidates to read the handbook cover to cover, work from the examination subject matter scope in it, study about an hour a day and practice calculations.

For a residential paper, the calculation practice that pays is dwelling load work, branch circuit and feeder sizing, and box fill. Those are the arithmetic areas a house wirer does by habit and then has to justify with a section number.

Free on this site: the timed practice test, the topic sets, and calculators that show the working rather than only the answer.

Questions people ask

How many questions is the NC SP-SFD exam?

Forty multiple choice questions with a maximum of three hours. The pass mark is a minimum grade of 70 out of a possible score of 100.

Is the Residential Dwelling exam open book?

For two books. The 2020 NEC is required and the 2013 edition of NFPA 72 is allowed for this classification. The licensing law, the Board rules and the NASCLA guide are closed book.

How many hours do I need for SP-SFD?

At least 3,000 hours of experience, of which at least 2,000 hours must be primary experience. The rules count 2,000 hours as one creditable year.

What can I do with a Residential Dwelling license?

The scope is set in Section .0800 of the Board's rules in Title 21 NCAC 18B. Read that section rather than a summary, and ask the Board about any job that sits near the edge of it.

Is SP-SFD cheaper than a Limited license?

The annual license fee is $100 for a special restricted classification and $100 for Limited, so they match. The application and examination fee is $125 either way.

Can I upgrade from SP-SFD later?

The Board publishes a license upgrade application and a license downgrade application. Each classification has its own examination and its own experience floor, so an upgrade means meeting the higher floor and sitting the higher paper.

What this page cites

• NCBEEC licensing classifications The Board's list of the Limited, Intermediate, Unlimited and seven special restricted classifications, with the annual license fee for each. Read 5 September 2026. source
• NCBEEC Examination Information Handbook The Board's own candidate handbook. Source for the item counts, the time limits, the reference list, the marking rules, the identification rules and the retake wait. Read 5 September 2026. source
• NCBEEC examination application for new applicants The application that sets the age, the character statements and the experience hours for each classification. Read 5 September 2026. source
• Title 21 NCAC Chapter 18B, the Board's rules The rule set behind the experience hours, the definitions of primary and secondary experience and the minimum grade of 70. Read 5 September 2026. source
• NCBEEC fees and services The fee schedule as the Board prints it, including the $125 application and examination fee and the $25 examination review. Read 5 September 2026. source
• NCBEEC examinations page The Board's page on the qualifying examination: open book, the minimum grade of 70, the seven test center cities and the 90 day wait after a failure. Read 5 September 2026. source