How hard is the NASCLA exam? What it tests

What makes it demanding

• Breadth. Twelve subject areas run from contracts and site work to concrete, steel, wood, roofing, finishes and building systems. The exam draws on 24 listed references, and it may also ask about trade knowledge and general industry practice that no single book covers.
• Two areas carry the weight. Procurement and Contracting Requirements (31 questions) and General Requirements (25) are almost half of the 115 scored questions. Being strong in the trades alone does not carry you.
• Open book is not easy book. You bring your own references, and the clock keeps running while you search. The 330 minutes cover 125 questions in all, counting the 10 unscored pretest questions, which is about two and a half minutes each.
• A blueprint packet. A physical diagram and blueprint packet is handed out at the test center, so expect to read drawings as well as text.
• Editions matter for code questions. Code questions are based only on the listed editions. For other references, using a different edition is at your own risk, and conflicts are not grounds for appeal.
• Strict book rules. You may highlight, underline and index, but not write in your books, and only permanent tabs are allowed.

How it is scored

The bulletin lists 115 scored questions and a minimum passing score of 81. It does not say whether 81 is a count of correct answers or a scaled score, so we do not turn it into a percentage for you. The 10 pretest questions are not scored, and you cannot tell which ones they are. Results go to NASCLA's National Examination Database (NED), and the bulletin asks you to allow 48 hours for them to be entered.

What tends to help

1. Study to the outline. The NASCLA exam outline gives every area's question count. Put your hours where the count is.
2. Get and tab your books early. The reference books guide lists all 24 and the tabbing rules.
3. Practice by area. A single overall score hides a weak area. The NASCLA practice test shows how to read your score by subject area.
4. Time your lookups. Practice in your own tabbed books at about two and a half minutes per question, and note which misses were "couldn't find it" rather than "didn't know it".
5. Plan the attempts anyway. You get up to three attempts in the year after NASCLA approves you. See cost, scheduling and retakes.

A practice percentage is not a prediction of your result, ours or anyone's. Use it to decide what to study next. The NASCLA study guide lays out an eight-week plan.

Take the free 10-question check and see your score by subject area in minutes. It needs no signup and explains every answer.

The NASCLA Commercial course has a lesson for each of the 12 subject areas that shows which listed reference to open and how to apply it, original practice questions with every answer worked, and four timed practice exams of 115 questions on a 330-minute clock. Your scores come back by subject area, so you know where the next study hour goes. See the course.

Not affiliated with or endorsed by NASCLA or PSI. NASCLA and PSI are named only to identify the exam and its test vendor.

FAQ

Is the NASCLA exam open book?

Yes. You bring your own copies of the 24 listed references, and none are provided at the test center. You may highlight, underline and add permanent tabs, but not write in the books, and Post-its must come out.

How many questions are on the NASCLA exam?

125 in 330 minutes: 115 scored questions and 10 unscored pretest questions you cannot tell apart. The bulletin lists a minimum passing score of 81.

What makes the NASCLA exam hard?

Its weight on the business side and its clock. Procurement and Contracting Requirements and General Requirements are 56 of the 115 scored questions, and you have about two and a half minutes a question, lookups included.

Sources

Show the list

• PSI Candidate Information Bulletin 1458, exam format, content outline, reference rules and results, updated 7 Jul 2026. Retrieved 5 Nov 2026.
• NASCLA Commercial Exam, NASCLA. Retrieved 5 Nov 2026.