I've looked at the specifics of some of the tax breaks (roughly: no taxes on the increased value of the property for some number of years), but they mostly seem oriented towards speculators or commercial, rather than residental.

The primary impediment to residential renovation is typically cash on hand to initiate the project.

Which, if true, seems like something like providing a loan facility, borrowed against the future tax credit, maybe with the tax credit packaged for resale on the open market to offset the cost?

Presumably nobody (the homeowner, the neighborhood, the city) wants a house that's falling apart to stay that way.