Energy and Greenhouse Gas Savings for LEED-Certified U.S. Office Buildings

John Scofield,Jakob Cornell,Thomas Scofield,Tian Liang,Susannah Brodnitz

doi:10.3390/en14030749

Abstract

In this work, we present results from the largest study of measured, whole-building energy performance for commercial LEED-certified buildings, using 2016 energy use data that were obtained for 4417 commercial office buildings (114 million m2) from municipal energy benchmarking disclosures for 10 major U.S. cities. The properties included 551 buildings (31 million m2) that we identified as LEED-certified. Annual energy use and greenhouse gas (GHG) emission were compared between LEED and non-LEED offices on a city-by-city basis and in aggregate. In aggregate, LEED offices demonstrated 11% site energy savings but only 7% savings in source energy and GHG emission. LEED offices saved 26% in non-electric energy but demonstrated no significant savings in electric energy. LEED savings in GHG and source energy increased to 10% when compared with newer, non-LEED offices. We also compared the measured energy savings for individual buildings with their projected savings, as determined by LEED points awarded for energy optimization. This analysis uncovered minimal correlation, i.e., an R2 < 1% for New Construction (NC) and Core and Shell (CS), and 8% for Existing Euildings (EB). The total measured site energy savings for LEED-NC and LEED-CS was 11% lower than projected while the total measured source energy savings for LEED-EB was 81% lower than projected. Only LEED offices certified at the gold level demonstrated statistically significant savings in source energy and greenhouse gas emissions as compared with non-LEED offices.

Highlights

IntroductionOne of the most important problems facing humans today is that of climate change, driven by anthropogenic greenhouse gas (GHG) emission, which is due in large part to the burning of fossil fuels
We believe that the relevant question is not can, but do green buildings, on average, save energy and reduce greenhouse gas (GHG) emissions? Here we address this question for LEED-certified U.S offices
The scale on the left axis is in SI units (MJ/m2 ) while that on the right axis is in kBtu/ft2 units used in the U.S The error bars represent the bootstrap standard deviations of the means

Summary

Introduction

One of the most important problems facing humans today is that of climate change, driven by anthropogenic greenhouse gas (GHG) emission, which is due in large part to the burning of fossil fuels. In addition to CO2 , the burning of fossil fuels releases other pollutants, including CH4 , N2 O, SO2 , NOX , and particulate matter, all of which have negative environmental consequences, when released from thousands of buildings in urban centers [2]. When buildings switch from natural gas or other fossil fuels to electric energy, the accompanying pollutants are shifted to the electric power sector, which may or may not reduce total GHG emission (depending on the details of the electric grid) but does improve air quality by moving emissions sources out of population centers. Power plants do a better job of reducing pollutants (other than CO2 ) than do individual boilers and furnaces

Methods

Results

Discussion

Conclusion