Man I love how they build houses these days...

I have a bathroom with a shower and a double sink in the main part of my office that are all tied in together with just one main vent, no issues.

Double sinks share a pee trap, so it's no different than a single. In theory if sinks are close enough you could do the same but with sinks in different rooms I doubt it meets code. I'm pretty sure you can tie into the sink vent a certain way but I also think the size of the vent depends on the number of drains. Chances are the floor drain in the mech room is also sharing the bathroom vent and he's adding two more drains. So it's something to look into.

Well the house is 8 years old and maybe the previous owner did not bother where they put it :-(

I can weigh in on this one. As long as you use a sanitary-T then it meets code. I have this in my basement and it is one of the few things the plumbing inspector passed me on in the first attempt. This is a sink in a mini-kitchen area and a bathroom sink behind the wall and they share a rough-in.

My inspector didn't care so much about any of the water supply lines, only about how things drain and how they vent. So I'm reasonably confident in this assertion - however with the said, code can and does change from time to time.

If ever in doubt however, the best thing to do is ask the city inspection department. Call 311 and ask to speak to the permit inspectors, there will be a manager of the actual inspectors who come to you yours house on phone duty 8am to 4pm, you usually don't have to wait beyond a couple minutes on hold and then you can ask specifically about things that they can pass or not pass. Wish I had known this before my first inspection. I asked a licensed plumber about something and he told me it was code, only to find out it was not code after all and thus failed the inspection. You'd think the professionals would know but they don't always. Just go straight to the source. They'll tell you straight up what they are looking for.

Thanks Tony. So let me understand this. you need different drain for each sink?

It's sounds like you can tee them into one drain according to Tony but I was told you also need to run another vent from the new sink and tie that in a certain way as well. Was told if you just tee into the same drain pipe then draining one sink can end up siphoning the other sinks pee trap. Unless you can run a single pee trap but I was never given this option.

I know you cannot use a single P-trap, except for a kitchen double sink. If you have 2 bathroom sinks, they would each have thier own trap.

As for your vent, there is usually 1 or maybe 2 common vents in a house. All fixtures have to be vented properly. If you are adding something that is not close to the common vent get a licenced plumber to do it.

The AB code does require the permit for plumbing to be pulled by a licenced plumber. Electrcial you can pull & do yourself.

In Calgary you can get what's called a homeowner's electrical permit and a homeowner's plumbing permit. Ie., you can DIY if you want but they don't lay out the basics of code like they do for electrical. Ie., for electrical they give you a condensed version of the code which is sort of like an inspection cheat sheet (ie., like in school when the teacher say "this is what is going to be on the test.") They don't do this for plumbing, or at least they had nothing like that when I went through this last year. You're expected to know what you need to know, although with the inspections office accessible by 311 you can always phone and ask if you're not sure if something meets code or not.

The inspector never said anything to me about a separate vent from one of the sinks during my rough-in inspections, but then again I haven't had my final inspection yet either so who knows.

Oops, meant to post this link. Better late than never?
http://www.calgary.ca/PDA/DBA/Pages/...velopment.aspx