How to Analyze Slopes for LEED Certification in Neighborhood Development

Leadership in Energy and Environmental Design for Neighborhood Development (LEED-ND) is a certification program that promotes a green approach to community development. In fact, the US Green Building Council (USGBC) plans to designate LEED-ND as an American National Standard (ANSI). I first blogged about LEED-ND a few months ago where I demonstrated how to use buffer analysis to assess the density of an area based on the number of street intersections for LEED-ND certification. Recently, I posted a short video that introduced how to use geospatial analysis in LEED-ND certification efforts. Geoff Zeiss also blogged about LEED-ND and the progress being made towards finalizing LEED certification criteria.

This post looks at how to use geospatial tools to examine the suitability of a site in the Slope Protection category of the LEED-ND score card. The objective of this category is to minimize erosion of slopes to protect habitat and waterways by preserving steep slopes in their natural state. Specifically, one option to accumulate maximum LEED-ND accreditation points, requires that project sites avoid disturbing areas with slopes greater than 15%. A quick way to check whether a proposed site qualifies for maximum points in this category is to superimpose a 2D CAD drawing of the site and a 3D Digital Elevation Model (DEM) and then perform a simple thematic map on the DEM based on slope. Note that if you don’t have a DEM for your specific site, a quick web search reveals a number of sources for this type of data including the GIS Data Depot.

One of the key benefits of this approach is that candidate sites can be easily and quickly short-listed against specified criteria without huge expense. Another benefit is that better designs are possible because more candidate sites can be evaluated against LEED-ND criteria.

Check out the video to see the process in action using AutoCAD Map 3D.