The old zoning code was a product of 1970s ideas about separating different kinds of properties — residential all together in some areas, commercial in others — but it didn't recognize the reality of Baltimore, which was built up under different notions and different rules. It not only stymied the kind of new development people like but also made it more difficult to adapt old, non-conforming buildings to new uses that would be assets to the city. An old church in a residential neighborhood that was no longer used for its original purpose, for example, might make sense as a small office building, but the old code discouraged such a conversion, and making it happen was time consuming and unpredictable. The new code solves those sorts of problems.