Network/Telecom Techs, how is fiber in a downtown condo pulled (located in Toronto)?

Hello,

I'm located in Toronto, Canada and I was wondering how the fiber in a downtown condo wired/pulled. I know there's a main communication room in the building, but does each ISP have their own fiber lines that run to each unit? I'm assuming each ISP would have their own Optical Line Terminal and Switch in the communication to manage the ONUs which then goes to a fiber line to their data center, but the physical lines themselves that go throughout the internal wiring of the building, who owns that? Is it part of the building's commons and anyone has access to it or does each ISP pull their own lines?

So say if 3 different ISPs (in my case, Bell, Fiberstream, and Beanfield) all offer fiber service in your building, did they all have to run their own lines? Or does the Telecom Tech that shows up have to pull a new line from the Comm-Room to the unit for that particular ISP and that ISP now owns the new line, or do they have an agreement with say Bell, who might have done the initial wiring during construction or a retrofit and they lease the line?

I'm just trying to understand when a customer orders fiber to be installed into their unit, is all the fiber in the building pulled ahead of time and the tech just terminates the OLT/ONU connections because those lines are owned by their ISP (or is it owned by the building, please clarify) or is the tech pulling a new line from the communication room to the unit. For example in my building, there is no fiber jack in the wall (only phone and coaxial) but I know there is fiber service in the building (from those three companies) so where is the line coming from?

Thanks!