Carbon Footprinting and New Urbanism

Yesterday afternoon a group of like minded people gathered to hear Jennifer Langford, an local architect and the regional representative for the Congress of the New Urbanism speak breifly and lead a discussion about how location matters to sustainability.  It was a discussion sponsored by the Heart of Florida's USGBC LEED for Homes Advocacy Committee.  The discussion started with the obvious -- when you live in a more urban environment, you are closer to basic services, you can connect to existing infrastructure, you are not using up precious greenspace.  We moved on to more specific topics, including energy usage in homes in a more urban environment.  This topic had me wanting to compare neighborhoods. 

If you go to the new Gainesville Green website you can compare your energy usage (if you are a GRU customer) to your neighbors, and you can compare entire neighborhoods.   By looking at this site you can see that in the Haile Village Center, the average carbon footprint, measured in tons of CO2 per month, averages a bit less than one ton for the average house.   In the Haile Village Center, homes are anywhere from a few feet apart to attached.   In a similar neighborhood, Stratford Ridge, in terms of the size of the houses (although the houses are newer and should therefore be more energy efficient), the average home has a carbon footprint of 2.7 tons of CO2 per month -- a significant difference.   The Village Center does have more diversity in terms of house sizes, but the median is similar -- slightly higher in Stratford Ridge, but not higher enough to justify over twice as much carbon footprint in utility use. 

So, why is it different?  The Village Center has older houses, many with single pane windows, less efficient insulation, and some with raised wood floors.    However, they are typically designed in standard block shapes, with architectural interest being supplied by windows with depth and with deep porches.  Windows are plentiful, but are shaded by the porches or by the tall neighborhing houses.  Houses are up off the ground (which provides some privacy in a tight neighborhood) and are almost all two stories with full attics.   The ratio of roof to overall square footage is low.  Much heat gain (and therefore energy usage) in Florida comes from the roof and windows, so if your windows are shaded and your roof is small, there is greater efficiency.  

And it is not all about energy.   Water usage in the Haile Village Center averages around 5000 gallons per household year round.   In Stratford Ridge, water use per house averages 20,000-30,000 gallons per home through out the year, with a peak in June of around 60,000 gallons.  There are no lawns in the Village Center, only shared green space nurtured with reuse water.  Stratford Ridge has abundant lawns and swimming pools. 

The point of this post is not to pick on Stratford Ridge where there are lovely homes, but to point out that there are more environmental costs to building sprawling homes on large lots.   Everyone thinks that New Urbanism contributes to a lower carbon footprint because there is less dependence on the automobile, but really, it is much more than that.   While it is great to be able to walk to stores, restaurants, bars and even to your office, it is also great to not have a lawn to mow and water, to be sheltered by your neighbors, and to have only a fraction of your home bear the full brunt of the Florida sun that we all love so much.