Comparison of Commercial LEED Buildings and Non-LEED Buildings within the 2002-2004 Pacific Northwest Commercial Building Stock

David Baylon and Poppy Storm, Ecotope, Inc.

Keywords

Abstract

The percentage of new commercial buildings that seek certification under the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED®) has been steadily increasing over the past five years, with several jurisdictions now requiring the use of the LEED standard for all new buildings. As part of a larger New Commercial Baseline Study examining 345 randomly selected buildings throughout the Pacific Northwest, we examined the building and performance characteristics of 24 LEED buildings constructed between 2002 and 2005 in Washington, Oregon, and Idaho. The paper directly compares the characteristics of the LEED buildings to a larger sample of buildings in a field study of building practices across building types and states. Most of these buildings had been occupied at least two years.

The components of the study included:

A plan and field review that included determining floor area, mechanical equipment, lighting fixtures and lighting power, and envelope characteristics.
Collection of energy use data to determine the overall energy use intensity (EUI) of each building.

This paper provides an overview of the building characteristics and overall energy use in the LEED buildings included in this study. The EUI and other characteristics are compared to the larger sample of buildings collected from the random sample of new buildings and to previous regional samples.

Whereas typical LEED comparisons focus on differences between LEED building features and national code (or building performance and initial modeling), this paper is focused on the regional relevance of the LEED standard and implementation. Summaries of building characteristics reveal a pattern of consistent improvement in lighting and mechanical systems and a pattern of consistent increase in glazing area partially offsetting these engineering gains.

The LEED buildings in the sample had an observed performance only about 12% better than performance for the comparable buildings from the remaining sample. This may be partly due to the more stringent Oregon and Washington energy codes and partly due to performance offsets from glazing and control issues.