First of all, you may not legally be permitted to make an alteration to the system.

In most jurisdictions any multi-family residential structure which is greater than 3 stories in height or which has four or more living units is considered a "Commercial Residential Structure."

In recent years we have seen a lot of apartment complex's go condo and this has created a real gray area in the zoning restrictions. In some condo purchases each owner is a member of a corporate agreement to maintain the common areas of the structure and grounds while in other situations when you purchase your condo you only get title to your individual living unit while there remains an owner or property manager that oversees the common areas. In order to perform any maintenance or alterations on the utilities from the point where they enter the structure to your living unit you must be a bonafide owner of the common area or you must be an employee of the owner of the common area.

The laws further define that an owner or employee of the owner may only perform maintenance. By definition, maintenance is the act of repairing or replacing the existing components but you may not alter the original design in any manner.

In order to make alterations to the original design no matter how slight, you MUST BE a licensed commercial plumber. (those licensed solely as residential plumbers may not work on these structures).

For years the commercial codes have required that all commercial multi-family residential structures must have either a separte water service or an individual shutoff to each living unit.

You stated that you do not know where the main water line enters your living unit. The first step would be to locate that line and you will most likely find you already have the individual valve you desire. It may be in a common utility space, in a service access panel in the ceiling in the hallway, a janitors closet in the hall or even underground just outside your unit.

Thanks for the info lazypup. But for this project, I have done my homework and have not been a lazypup. I can do it or have it done, its just a matter of isolating my supply line and figuring how involved it will or wont be. And no, there is no other water shut off besides the main valve that shuts off two buildings (eight units). Trust me, I've checked it out.

I hope this isnÂt just because youÂre in California. Sometimes they can be a bit, ahm, odd. I find it unthinkable that the case is just as you said, but it could be. It is a no-brainer that each unit needs its own shut-off.

LetÂs begin at the beginning. I think you may have pointed to an important consideration asking this question, "What I would like to do it install a shut-off valve where ever my supply comes into my unit or branches off from the main supply, or whatever the case may be. But thatÂs the part that I'm unsure off. Where would my supply line come into the unit?"

If each unit pays for their own water, there will be a water meter there. That is where the water comes in and an excellent place to shut it off.

Pinoke

Nope pinocchio, I guess I should have thrown that part in but I just kind of assumed it was obvious. Thats the one good part in all this. The water (and garbage) is paid by the hoa. Of course, we all pay for it, just not directly. There is a meter on each main supply line that feeds two buildings.
Just by the way the buildings are designed, I'm thinking that my supply line branches off from the main line and runs through the garage. I might just have to do some playing around with it and figure out whats what.
And yes, you are correct. We are a bit odd here in California. Guess thats part of the reason I paid over $400k for a condo and I don't even get my own water shut-off. :)

Four hunnert kay. Wow, that must be some kind of wonderful place. Are those US Dollars? IÂve got a SIL, lives in SoCal. She entered a condo agreement and the property value is rising so fast, the mortgage is mostly tax escrow.

Well, I think itÂs time to get a real live person on your case, CAP. Someone who can see the works or knows the history, not necessarily a professional. In fact, at this point, I would still look for a casual assessment of the service.

It seems to me the HOA is a good resource for you. Your issue is the same for each homeowner. All share this need. Eventually, if you make the improvement, it could be part of a much larger project, shared by all and cheaper for each and everyone.

Meanwhile, look in another place. Where your HOT water begins is a natural place to begin the COLD. I would expect to be able to shut OFF both in the same place or very nearly so. If you see that the heater has a valve on the COLD line, you can look for a valve that would do double-duty.

Pinoke

The water (and garbage) is paid by the hoa. Of course, we all pay for it, just not directly. There is a meter on each main supply line that feeds two buildings.

There will be at least two shutoffs then, one for each main.
And it is going to be very involved since it will mean shutting down whichever main you are one (thus affecting the other units, which I doubt the HOA would allow). Plus you will still have to pay a plumber (provided you can find one to touch it). Oh and of course permits and associated fees.

Hmmmm, maybe I'm not explaining correctly. There is currently only one shut-off that I would need to access to shut off my building (and the one next door). Other buildings, besides these two, have their own.
Its no more involved than the times I've had to shut it off before when I changed a water heater or had some plumbing done with my kitchen remodel. But thats what I'd like to avoid, having to inconvenience others when I want to shut it off. And I've got atleast one and maybe two bath remodels for next year. Probably going to have to shut it off atleast a couple of times for each one.
And then there was the time when a friend and I were demoing the kitchen. I made a run to the store real quick and 5 minutes later he frantically calls me wanting to know how to shut the water off. Turned out he managed to snap the old angle stop off the cold water supply line that feeds the sink. I came back quick and there was water all over. Well, we still had all the old stuff piled up in a corner, so I cut off a piece of the dishwasher hose, fed it back onto the broken end of the pipe and stuck that down the drain for the sink. But then we had to go to the hardward store, get what we needed, come back, let everyone know we had to shut the water off for a quick emergency repair and then did it. Would have been easier with just a disconnect in the garage.
So, as far as HOA goes, they don't really care. They just want people that do have to shut it off to let everyone affected know as soon in advance as possible. And yea, I do realize I'd have to pay a plumber to do it. Best thing to do I now realize is call a few plumbers and get estimates.

I'm very late to this party, but if anyone else sees this thread, I am in this particular boat as we speak - except different state and shorter building. We're essentially quadplexes (4 units, 2 floors) and each building shares one shutoff valve. I wanna get my own in my unit so that my three neighbors don't have to be without water just because I wanna remodel my bathroom. I'm wondering how much effort that is, AKA how costly it is to get one installed.