Which condition would automatically make a non-conforming structure conforming?

A non-conforming structure refers to a building or use that was legally established but no longer meets current zoning regulations due to changes in the law. The condition that would automatically make such a non-conforming structure conforming is a change in the zoning laws that favor the existing structure.

If the zoning laws are revised to allow the previously non-conforming use or structure, the building immediately becomes compliant with the current regulations. For instance, if a residential area previously prohibited certain types of housing but is re-zoned to allow them, any structures that fit the new criteria would now be considered conforming.

The other options do not alter the legal status of a non-conforming structure in terms of compliance with zoning laws. Emergency repairs, adding a new storey, or upgrading systems may improve the building or maintain it but do not address the underlying issue of compliance with zoning regulations. Thus, changes to zoning laws that favor an existing structure directly result in its conformity.