Planning is just like other professions – it’s subject to the “bandwagon” effect. A new idea comes along – usually a good one that addresses some important weakness in the current system. People take notice because it seems to work – it solves a problem the profession was trying to solve. That’s when the bandwagon effect kicks in. Not only is the new idea a good idea if you are facing that particular problem – all of a sudden no project is complete unless it includes the new idea. The new idea comes up in planning commission meetings, maybe even in city council meetings – usually in the context of “that’s a good idea, why don’t we have one of those in our system?” The problem with the bandwagon effect is that it stretches the logic of the new idea beyond the problem it was intended to solve. All of a sudden planners have to start explaining why they don’t use the new tool – even if the answer is “it really isn’t designed to address this problem. This problem calls for a screwdriver and that’s a pair of pliers.” But planners work for elected officials, and once they start asking the “why don’t we have it?” question it’s often easier to say “we’re working on that right now” instead of explaining the difference between a screwdriver and a pair of pliers.

Form-based zoning is one of the latest examples of a popular planning idea. And it’s a really good tool in some circumstances. 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. Clearly, zoning that focuses on acceptable land uses might be missing the point. But building a 15-story residential tower in a townhouse area, or a shoppette with parking in front right in the middle of a block of storefronts that you can enter right from the sidewalk – now that could be a problem. The new “form” could erode the character of the area and destroy the very things that make it desirable — a human scale, or walkability, or back yard privacy. Where an urban area has a definable character and form, form-based zoning may make a lot of sense.

But there are many areas of most cities where it is hard to find that form. Areas where there is a true mix of forms and styles. Row houses are mixed with single family buildings and apartment buildings – and the citizens like it just fine. Areas where a high-rise building is clearly out of scale with everything around it, but the neighbors have gotten used to it and actually like it. If another high-rise came along they would like that just fine, too. Areas that are in transition, where 70% of the “urban fabric” points to one style and the remaining 30% is a complete mix of mid-rises, high-rises, shoppettes, institutions with parking around them, and whatever. A skilled urban designer could look at the area and say that the dominant urban form is “X” and that should be reinforced. Or that it’s “X on the way to being Y” and that should be encouraged. But the neighborhood residents might disagree with both. Yes, it’s not a definable form, and yes it looks like a mess, but we like it that way. There are areas where the clear preference of the residents is not to have a particular form that you are trying to reinforce or work toward. And it’s not clear why the city should push for a different result.

I think this underlines one of the important disconnects in planning. Planners are trained to look at neighborhoods and see what they “could become” and urban designers are trained to study form and decide what the form “should be”. Sometimes that is exactly right – but not always. Cities are complex places, full of residents and property owners with different and conflicting goals. Isn’t it just possible that some areas could be happy without being on the way to something different? And that would be just fine for the future of the city?

That’s why form-based zoning is a great innovation – some of the time, and in some places. But to jump on the bandwagon and say that form-based approaches can cure the ills of zoning is overstating the case. It cures problems related to over-focusing on uses and under-focusing on building form in areas that have or want to have a particular urban form. But that’s not all of the city – and it may not even be a majority of the city. Like any legal tool, form-based zoning needs to be used thoughtfully and carefully. And that’s why most major of America’s major cities have chosen to use form-based zoning selectively – rather than trying to apply it everywhere.