If the buildings without sprinklers really are putting their occupants at risk, then units in those buildings are worth less than otherwise comparable buildings with sprinklers.  I suspect that they are not assessed at less.  If that is so, then the city council should take the difference in tax between what owners of units without sprinklers pay, and what they would pay if the difference in value was incorporated in the assessment, and put that money into a special fund that those condo associations can draw on to upgrade the safety of their buildings.  If buildings without sprinklers are in fact assessed at less than comparable buildings with sprinklers, the City Council should gross them up to the assessment they would have if they had sprinklers and put that money in a fund the building associations could draw on.  Either way, the buildings would have a strong incentive to submit plans to install sprinklers or otherwise make the buildings safer to get their money back.