Here’s a potentially good idea about which I’m rather ambivalent: rules requiring in-city developers to include robust landscaping features such as green roofs and vegetation-covered walls. It’s easy on the eyes, but it may not be smart public policy.

To begin with, it’s unclear how much burden Seattle’s cutting-edge new rules would impose; and it’s unclear how much benefit they’d achieve. But if most developers are skeptical — and they are, at least according to this article — then policymakers should listen very carefully.

Burdening developers with additional layers of regulatory complexity, especially here in regulation-heavy Seattle, may not be such a hot idea. Those regulations tend to reduce the viability of further in-city development or raise the cost. Either is bad.

No, I haven’t been reading Milton Friedman over the holidays. It’s just that when it comes to urban development, I’m not sure that we need a lot of elaborate new policies and procedures. In some case, we simply need less red tape.

Here’s why …

The most environmentally sensitive thing we can do in urban design is encourage more density in places that allow us to live lighter on the land. That means giving people an opportunity to live, work, and do business in places where tennis shoes substitute for gas tanks. (Generally, those are also places where people consume less land and also use less energy heating and lighting their homes.) To encourage that sort of environmentally beneficent way of living, the smartest public policy may be to to slash well-intentioned but unnecessary obstacles to development. Minimum parking requirements leap to mind. There are dozens, perhaps hundreds, of others.

Construction costs are already spiking and urban affordability is already a serious problem. Sprawl is accelerating in places where land is cheap and regulations are minimal. So unless we have a really good reason (and there certainly are some) we should avoid making it more expensive to build commercial real estate or multi-family housing in urban areas.

I guess I should mention that I’m hardly opposed to green design for managing stormwater runoff or to achieve other benefits. (In fact, I’ve been semi-obsessed with the issue lately.) In many cases, environmentally friendly design may actually be cheaper and more efficient than conventional alternatives. Trees can cut down on air conditioning; swales can ease drainage loads; and studies have shown that urban vegetation has social and economic benefits too.

So there’s all that. But some policies have unintended consequences that may actually be counterproductive; and getting a handful of green roofs is not worth discouraging development in pedestrian-friendly neighborhoods.

Let’s call it the Ockham’s Razor of environmental policymaking: sometimes the smartest thing we can do for the environment may also be the simplest.