For those not familiar with it, the California Title 24 Building Standards Code consistes of 10 fairly hefty binders containing over 4,614 pages of small text.
- Part 1: Administrative Code (231 pages)
- Part 2: Building Code (2 Volumes, aprox. 1,600 pages)
- Part 3: Electrical Code (829 pages)
- Part 4: Mechanical Code (419 pages)
- Part 5: Plumbing Code (516 pages)
- Part 6: Energy Code (110 pages)
- Part 7: Elevator Safety Construction Code (merged with other parts)
- Part 8: Historical Building Code (40 pages)
- Part 9: Fire Code (579 pages)
- Part 10: Existing Building Code (32 pages)
- Part 11: Green Building Standards Code (80 pages)
- Part 12: Referenced Standards Code (178 pages)
The entire set costs a little over $1,000 and Architects are expected to know or at least be aware of all of it. Not surprisingly, a lot of our time is spent scouring over the code trying to make sence of it all.
Yesterday a coworker of mine and I stumbled across this little gem of the building code when designing the threshold into an accessible shower stall for an apartment building.
- Showers within a unit, outlined in section 1134A.6 #5:
- “When a threshold is used, it shall be a maximum of 2 inches (50.8 mm) in height and have a beveled or sloped angle not exceeding 1 unit vertical in 2 units horizontal.”
- Showers located in common facilities, like lobbies, clubhouses, game rooms, etc. are described in 1127A.5.3 #2:
- “When a threshold or recessed drop is permitted, it shall be a maximum of ½ inch (12.7 mm) in height and shall be beveled or sloped at an angle not exceeding 45 degrees (100 percent gradient) from the horizontal.”
- Showers in commercial and public buildings are referenced in section 1115B.4.4.2.
- “Thresholds in roll-in type showers shall be ½ inch (12.7 mm) high maximum and shall comply with Section 1124B.2.”
- Section 11124B.2 talks about all level changes: “Changes in level up to ¼ inch (6.4 mm) may be vertical and without edge treatment. Changes in level between ¼ inch (6.4 mm) and 1/2 inch (12.7 mm) shall be beveled with a slope no greater than one unit vertical in 2 units horizontal (50-percent slope).”
I understand the logic of making the restrictions less stringent, 2″ for private units then 1/2″ for common and public spaces. But why the more stringent 1:2 sloped bevel for private uses, then the more relaxed 1:1 slope for common spaces on private property and back to 1:2 slope for public spaces?
Why not just make it all the same and make things easier for all of us?
Just a little disclaimer: The content of this post is my interpretation of the code. I may be 100% wrong so don’t use this to design anything.