I like this idea. However it would be very difficult to implement without people exploiting it. I can imagine someone building a 3x3 hewn cube, slapping a painting on it and calling it a day, and then getting their entire to town to vote on it as "historic" to farm culture. Perhaps only count votes from non-citizen. Your town can mark what structure is historic, and only with outside votes, will it actually gain historic status.
Much like paintings, I suspect the voting system will be heavily biased in favor of non-citizens. Votes will also consume from a player's daily allotment, so each player will need to consider if they want to allocate their votes towards a painting, a player, or a building. It would still be possible for different towns to negotiate 'vote trading', but that really isn't so different from the art trading which currently happens.
I dunno, my "historic buildings" are historic because they are there since the beginning of the run, evolving and upgrading as better materials become available. It is only possible to become colorful enough due to modern materials, but parts of the original remain. Therefore, if anything, it's the MIX of materials, Tier 0 through Tier 4, and the fact that SOME parts of the building have stayed unmoving for days, if not weeks on end, that give it the historic status. Refurbishing should be a merit, not a hinderance to our heritage.