According to the Daily Herald, a proposal is being discussed in Columbia to scrap the 400 page zoning ordinance (fairly recently written as I recall) and go to a form based system. As one planning blogger explains:
The basic idea is that zoning has gotten too pre-occupied with fine grained differences in land uses and has lost site of the “form” of development. The real issue may not be that the land use is inappropriate, but that the form of the building doesn’t fit in with those around it. Look around any dense urban area – particularly a downtown or a transportation hub – and you can find a very broad range of land uses. Offices, apartments, stores, condominiums, clinics, gas stations; how could any proposed use be inappropriate? This is an area where everything goes on.
On the other hand, many areas have a mixture of forms as well as land uses. Picking a predominant "form" can be more difficult than at first supposed. And of course, whatever the form, many land uses have significant impact that cannot be ignored. Finally, here in Tennessee, recall that the Non-Conforming Property Act, Tenn Code Ann Section 13-7-208 greatly restricts what a city can do with non-conforming properties. The statute protects not just uses, but building forms as well.
Form based zoning is a good tool, but not in all situations and at every location. It should be used with judgment and discretion.