I am doing a remodel. Below is a sketch of the waste and vent for the water closet (W.C.), with the 2" or 3" ABS shown as solid line. There is a window directly above the W.C., so the vent has to travel sideways for at least 40" before going completely vertical. I don't see anything in the IPC or UPC about W.C. venting using a yoke vent as shown. The UPC is the local code. I will be replacing the old high quality, high flow toilet with a low flow toilet, as parts are no longer available for the old one.
1) Is the yoke vent as shown allowable within UPC? Is there a maximum allowable vertical distance from the W.C. to the yoke vent?
2) The horizontal vent section is about 12" long and is below the W.C. Is that allowed by UPC?
3) The dashed line indicates a possible reroute that would remove the horizontal section of vent. Is that a good idea in order to better meet code and minimize chances of future vent blockage?
4) If these arrangements do not meet UPC, does anyone have a better idea of how to drain & vent?