I’m not a lawyer so take this with a pinch of salt (or call someone who is) but if work is being done to the building that is to the benefit of all the owners then it is clearly unfair that only a minority of owners should suffer the financial penalty of loss of rent.
I agree with Sir Humphrey (Post #2) and the loss of rent should be borne by everyone equally (or in proportion to their unit entitlements) so you and your fellow top-floor owners should be looking at forcing the OC as a whole to share the burden.
If the powers that be choose not to offer a reasonable settlement, talk to a specialist strata lawyer.