Mapping LEED ND Sites In and Around Boston
Author: David Scheltz
LEED ND is a recently-released development rating system, published by a coalition of the Congress for the New Urbanism, the US Green Building Council, and the Natural Resources Defense Council. Its overarching goal is similar to LEED, in that it seeks to encourage environmentally sound development. Unlike previous LEED systems, however, LEED ND looks beyond the performance of a building by emphasizing regional and neighborhood-level objectives. Chief among these is to reduce vehicle miles travelled (VMT). Distilling the worthy concept of sustainability into a set of objective measurements,however, is no easy task. Rather than describing myself how the scoring system attempts it, I encourage you to download the document from the USGBC's website.
LEED ND's top priority is encouraging developments that reduce the demand for vehicle travel. The question I pose is: how successful is the system likely to be? A critical first step is actually mapping sites that would be eligible under the LEED ND criteria. I have chosen the Massachusetts Bay area for my analysis. Then we can study the eligible areas and think critically about whether or not development in those locations would generate less vehicle travel and/or promote more walking and transit use, based on what we know of the relationship between travel behavior and the built environment.
There is much more to LEED ND that just the site selection. Most of the system deals urban design and building-level qualities, so this analysis cannot provide the final word on LEED ND's suitability. Still, as my probability professor liked to say, "all models are wrong, some are useful". I hope you will find this model useful, and I encourage you to download it, learn from it, and improve upon it.
- Overview of Spatial Analyst
- Modeling Spatial Problems with Spatial Analyst
- A Whirwind Tour of Geoprocessing
- Paul Cote's Winter Olympics Tutorial. A great introduction to raster analysis techniques I use in the model
- Paul's earth shelter tutorial which builds on raster techniques introduced in Winter Olympics. Hopefully it will give you ideas for how to improve my work!
- Assessing LEED ND, the accompanying research paper that contains the results of the GIS analysis and conclusions.
Purpose and Question
The purpose of this model is to map sites that meet LEED ND's location prerequisites. Roughly speaking, these require that the site be:
- infill development or
- in an area with good street connectivity or
- nearby to diverse uses or
- well-served by transit AND
- respectful of important natural resources, including wetlands, prime agricultural areas, and species habitats
Exploring the Model
Open the LEED_ND_GIS folder. You'll see that this folder contains
- folders for data sources
- folders for the output data that the tools create ("infill_output", "adjacency_output", "transit_proxy_output", "use_output", and "eco_output")
- the LEED ND toolbox (a .tbx file)
- a .mxd file that brings it all together.
The slideshow below shows the 4 resulting maps for each of the 4 tests, plus the overlaid "environmental criteria" layer.
Parting Thoughts/Areas for Improvement
If you take the time to look through the LEED ND manual, you'll find that the scoring system is very complex. This model only approximates the Smart Location pre-requisites. Here are the areas I see as most important for improvement: