Thursday, January 8, 2009

Chicago - Interview with Greg Raymond

A lot of cities in this world have a lot of problems and Chicago is no exception. A couple years back, the city's mayor, Richard Daley, realized that a growing body of evidence pointed to green roofs as a way to reduce runoff, flooding, the urban heat island effect and air pollution. Either that or he was impressed with their aesthetic qualities on an European trip. Returning from the trip, he began a very well publicized push to dramatically increase green roofs in Chicago.

I had the chance to speak today with Greg Raymond, founder and chief of ecogardens, a leading Chicago based design/build firm that specializes in green roofs and gardens. It made for an interesting conversation and I've summed up the more critical points after the fold.

The green roof industry has enormous potential, but it is only economically viable if cities stop allowing developers and property owners to externalize the enormous costs of stormwater, increased heat exposure and air pollution. Greg told me that the only people making the decision to add green roofs were people who included an environmental component in their bottom line and institutions that had the lasting power to recoup their initial capital costs. Private developers are greatly reducing their interest in green roofs as the economy collapses and they don't have the capital to front for the 15-20 year payback.

The city, which mandates partial green roofs for all new public buildings but has no requirements for private buildings, seems to have allowed this issue to fall to the back burner. Aside from the apparently non-existent public money pledged to support capital costs, the city has no incentive system to encourage green roof building. European cities that have successfully fostered green roof development have done so by heavily taxing stormwater that leaves a development; that is reasonable since the city bears the cost of dealing with that water. Developers in those cities find buildings without green roofs hard to sell since they have significantly higher taxes. Chicago should get moving in that direction.

Greg told me that 75% of structural inspections, the first step of any green roof retrofit project, show insufficient building strength to carry the additional 20-30 pounds per square foot of dead load that a green roof requires. Talk about bad future planning. As buildings age, they must maintain the capacity to be upgraded without significant alteration. So while new buildings in Chicago don't typically have green roofs, they do have one advantage. A recent code change stemming from a porch collapse increased the live load requirement on Chicago roofs to 100 pounds per square foot. For some perspective, this is 250% of the live load requirements for parking garages. As far as I know, this regulation is not nationwide but it will greatly assist future generations of Chicago property owners who want to upgrade their buildings with green roofs.

Greg is hoping that federal buildings may see some stimulus money to increase energy efficiency through green roof construction.

The expense our society is willing to incur for the sake of acute human health (stronger buildings) relative to how little we are willing to pay to improve chronic human health always astonishes me. Green roofs keep sewage out of waterways, they decrease the need for polluting energy production and most importantly, they reduce the intensity of the biggest natural disaster killer, heat.

Since civil engineers have created a separate mechanism for addressing issues that affect their profession (International Building Code), I would recommend that the IBC increase roof live loads so that buildings built today will one day be able to support green roofs without extensive structural renovations. I don't see any reason why that change needs to wait for politicians to make fairly obvious policy changes.

As for Chicago, they need to get their act together. They certainly advanced green roof design at one point, but that crown has gone on to other cities. The priorities of the city's government no longer seem to include green roofs.


  1. Green roofs are COOOL -- check out this home in Tacoma WA.

    All new buildings should be designed to anticipate these green roofs for the future. I hope you'll pursue changes in International Building Codes to make this happen!