I am in the process of rebuilding my kitchen wall since the existing
plumbing was going through the cabinets. The new wall will be 4" thick
so I can run my plumbing through the wall and get the full use of my
NEW cabinets. Now I've got the wall up, I need to know if I need to
vent my plumbing for the sink and dishwasher.. I've got 1.5" ABS
sloping down along the new wall to the existing ABS in the wall
directly beside it. Should I run straight up from the sink area and
across the new wall back into the same drain line but 5 feet higher
with a T?
Since there was no existing loop vent, I'm not sure I need the line
going up and across.

(see below) O=Sink

old and current setup-- | vent
|
|
|
O--DW-----------------|
|



vent | --is this right and/or necessary?
/--------------------|
| |
| |
\O----DW-------------|
sink |

Any input or help is greatly appreciated - I'm in Toronto, ON Area BTW.