Cabinet and Finish Carpentry (C-6) · Lesson 4 of 6

Accessible Sink Cabinets: Counter Height and Knee Clearance

"Accessible Sink Cabinets: Counter Height and Knee Clearance" is lesson 4 of 6 in the Cabinet and Finish Carpentry (C-6) Learning Hub. It opens with "When This Applies" and works through 5 short steps, then a worked example you can check yourself against.

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Steps in this lesson

  1. When This Applies
  2. Counter Height Limit
  3. Knee and Toe Clearance
  4. What the Cabinetmaker Does
  5. Check It With a Tape

The worked example in the course applies this lesson to a realistic job in 6 steps, from "Counter height" through "Pipe protection".

What you'll be able to do

  • Explain the main idea of "Accessible Sink Cabinets: Counter Height and Knee Clearance" in plain language you can use on the exam.
  • Apply this step with confidence: "Knee and Toe Clearance".
  • Apply this step with confidence: "What the Cabinetmaker Does".
  • Apply this step with confidence: "Check It With a Tape".
  • Test yourself on the worked example and the quick-check quiz inside the classroom.
Accessible Sink: Height and Knee Space COUNTER 1-1/2 in APRON 3 in KNEE SPACE 17 in deep 30 in wide min FRONT EDGE 29 in MIN 34 in MAX Insulated drain and supply pipes COUNTER HEIGHT (CBC 11B-606.3) Counter front at most 34 in above floor Top 1-1/2 in thick, apron 3 in tall Apron bottom = 34 - 1.5 - 3 = 29.5 in 29.5 ≥ 29 in at front edge: PASS KNEE AND TOE SPACE (CBC 11B-306) Width: 30 in minimum (36 in bay: PASS) Depth: 11 in at 9 in high, 8 in at 27 in Here: 22 - 5 = 17 in clear: PASS Pipes under the sink insulated (CBC 11B-606.5), no sharp surfaces Counter 34 in, apron bottom 29.5 in, knee 30 in wide: PASSES A 4 in apron gives 28.5 in and would FAIL the 29 in front-edge height Sources: 2025 California Building Code 11B-213.3.4, 11B-606 and 11B-306.CC
The diagram for this lesson, exactly as it appears in the Learning Hub.

The first steps of this lesson

Step 1: When This Applies

Chapter 11B of the 2025 California Building Code (CBC) covers public buildings, public accommodations, commercial buildings and public housing. CBC 11B-212.3 requires at least 5 percent, but no fewer than one, of each type of sink in an accessible room to comply with 11B-606, and 11B-213.3.4 requires at least 10 percent, but no fewer than one, of the lavatories to comply. The plans call out which ones. A stock closed sink base is not acceptable at those fixtures, so confirm with the designer before you build boxes.

Step 2: Counter Height Limit

CBC 11B-606.3 requires the front of the higher of the rim or the counter surface to be no more than 34 inches above the finish floor. Exception 2 permits an adjustable-height sink in a residential dwelling unit kitchen, 29 inches minimum to 36 inches maximum, where rough-in plumbing allows connections at 29 inches. A 36-inch counter fails the 34-inch limit by 2 inches.

The remaining 3 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.

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