Planning on a bathroom with a freestanding tub, in front of a shower enclosure. Double sink adjacent and next to it the WC.

- The basement has a rough in vent, but about 20 foot away in other portion of basement.
- Directly above planned bath is upstairs bath. I do see the trap for the tub coming through the floor, with a wye. Is that a vent or the tub overflow? If it's the vent, can I use that for the basement bath?
- Is a double sink considered two fixtures?
- Can I AAV under the double sink?
- Can I AAV the shower behind wall, with access and register on other side of wall (storage room)?
- How to vent the freestanding tub?
- I will cut up concrete and reroute existing rough-in

