Whew, this brought back flashbacks . . . I used to do construction lit, representing associations.

First, read the CC&R's with a particular eye to responsibilities. Generally, condo, horizontal property regime, or other names for this type of property designate who is responsible for what.

Typically, owners are responsible for things within the demising wall paint's skin, except for load bearing/structural items and certain utility items such as a supply and waste water piping; chilled water and HVAC systems.

Once had a case in a high rise condo building where a ground floor unit had an interesting problem. One of the bathrooms had a cabinet mounted above the toilet tank. In the summer, you could lift off the tank cover, but in the winter the tank cover was so close to the bottom of the cabinet you couldn't remove it.

The structural engineer had two opinions . . . the ground floor slab was rising and falling, OR that corner of the building was deflecting/sinking. We hired surveyors to "shoot" the exterior corner soffits of each floor with a laser to verify that the building was not deflecting.

It turned out that the slab beneath the unit was moving up and down based on the amount of water getting to the adobe soil underneath it. We also tracked the other source of the problem: during the testing of a a dry standpipe for the sprinkler system, the contractor had a broken/leaky supply pipe running under the slab. Nobody knows how many gallons of water got pumped into the soil before they figured out the pipe was no good.