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Weekly UpdatesTHE COMMERCIAL AND RESIDENTIAL SECTORS both have an important role to play in any worthwhile attempt to decrease the overall energy consumption of the United States. Often, the residential sector is too fragmented to provide real, economically sound returns on investment in increased efficiency or overall decreased consumption of energy without direct or indirect subsidization. A good example is the common use of demand side management programs, administered and funded by local and regional utilities, in conjunction with various state-funded subsidies. Until recently, the use of either direct or indirect subsidies was the chief mechanism to push for change in the residential market. This paper addresses the situation in a Florida context, but the issues have national application.
RESIDENTIAL GREEN BUILDING CERTIFICATION PROGRAMS
"Green certification" programs at both the national and local levels are trying to provide an avenue for increasing brand power for premium pricing while attempting to encourage appropriate energy and resource reduction options. In our studies we have concentrated on the ENERGY STAR[R] certification developed and administered by the U.S. Department of Energy and the U.S. Environmental Protection Agency because of its longer track record and robust building performance concentration. ENERGY STAR has the largest number of residential units certified, with an estimated 12 percent of new homes achieving the certification. (1) This is important because it allows a large enough number of data points to obtain meaningful statistical outcomes. We also selected ENERGY STAR because of its robust third-party verification through the use of Home Energy Raters (HERS) trained and certified by Residential Energy Services Network, a respected industry standard-setting body for residential energy efficiency. The ENERGY STAR system has been in operation since 1992, and a version applying to homes was started in 1995. Other rating product certifications include the National Association of Home Builders Model Green Home Building Guidelines, the U.S. Green Building Council's (USGBC) Leadership in Energy and Environmental Design (LEED[R]) Green Building Rating System [TM] for Homes, and the local Florida Green Building Coalition's own building standards for residential construction, as well as numerous green building programs nation-wide.
ENERGY STAR is often referred to as a performance-based program, but in fact it is more accurately a prescriptive path program using the HERS index to model predicted performance. The term "performance-based" could be misleading in that actual energy consumption of homes is not measured post-occupancy or required for ENERGY STAR certification.
The homes that earn the ENERGY STAR designation must meet guidelines for energy efficiency set by the Environmental Protection Agency and the Department of Energy. ENERGY STAR-qualified homes are designed to be at least 15 percent more energy efficient than conventional homes. The ENERGY STAR Qualified New Homes program applies to total energy consumption for heating, cooling, domestic water heating, lighting, appliances and on-site energy production. ENERGY STAR-qualified new homes can include a variety of energy-efficient features such as upgraded insulation, high-performance windows, tight construction and ducts, efficient heating and cooling equipment, and ENERGY STAR lighting and appliances. These features contribute to improved home quality and homeowner comfort, and can lower energy demand and reduce air pollution.
LEED for Homes is a green building rating system product released by the USGBC that covers some performance, environmental and social welfare issues. Based on a highly successfully marketed green building rating system for new commercial construction, the hope is to achieve equal success in the residential market. LEED for Homes is aimed at a new home market interested in including sustainable design features.
While there are already a number of local or regional green homebuilding programs, LEED for Homes is attempting to provide national consistency in defining the features of a green home and to enable home buyers anywhere in the country to identity green homes. LEED for Homes was developed and refined by a diverse group of national experts and experienced green builders. The LEED for Homes Green Building Rating System measures the overall performance of a home in eight categories that include location, site, water efficiency, energy, materials, indoor air quality and education.
The National Association of Home Builders (NAHB) has developed voluntary Mode! Green Home Building Guidelines designed to be a tool kit for the individual builder looking to engage in green building practices as well as for home builder associations (HBAs) looking to launch their own local green building programs. This certification addresses the builder and the building process rather than the individual home. The system aims to organize the green design and construction process and help home builders incorporate more green building features into their homes. The NAHB Green Building Guidelines address seven primary sections including lot design and development, materials, energy, water, indoor air quality, homeowner education and global impact.
While the LEED for Homes rating system is geared to appeal to the final consumer, the NAHB is interested in embedding the green preferences into the product delivery chain. Given the current residential market, it remains to be seen if consumer price sensitivity will allow any significant uptake for the LEED or NAHB products.
It should be noted that none of these green residential certification programs are structured to measure or verify post-occupancy performance of the home. Thus they remain incapable of contributing to increasing our data pools for analyzing and improving on the real performance attributes of green residential buildings. Surprisingly though, many developers, lawmakers and government officials have become convinced, as a result of active marketing campaigns, that a green rating will serve as a credible proxy for post-occupancy performance. Given the nature of the green certifications at present, only the ENERGY STAR qualification procedure, primarily because it is based on an actual testing and verification of certain crucial attributes of energy performance, provides some initial assurance of subsequent energy performance. It should be noted that ENERGY STAR figures prominently in the energy efficiency sections of the LEED and NAHB rating system as well.
FLORIDA LEGISLATION
On July 13, 2007, Florida Governor Charlie Crist concluded the first Florida Summit on Global Climate Change by signing three executive orders. Many of the ideas in the executive orders are directly and significantly changing Florida's building construction practices. Among other things the governor ordered Florida's Department of Management Services to "adopt the USGBC's Leadership in Energy and Environmental Design for New Construction (LEED-NC) standard for all new buildings," and he precluded all state agencies from leasing "office space that does not meet ENERGY STAR building standards' (2) He also established "greenhouse gas emissions reduction targets;" directed the Florida Department of Environmental Protection (DEP) to achieve "adoption of a maximum allowable emissions level of greenhouse gases for Florida's electric utilities;" and directed the Department of Community Affairs to revise the "Florida Energy Code for Building Construction to increase the energy performance of new construction in Florida by at least 15 percent from the 2007 Energy Code." (3) Finally, he established the Florida Governor's Action Team on Energy and Climate Change with a mandate to recommend legislative policies in specific areas--for example, "market-based regulatory mechanisms, such as cap and trade, for use in efficiently reducing greenhouse gas emissions" (4)
One year later, at the second Florida Summit on Global Climate Change, Governor Crist signed Florida House Bill 7135 into law, enacting new energy and climate change policies. Sections 17 through 22 of the energy bill codify the green construction standards outlined in the governor's executive orders, specifically requiring all design, construction and renovation of state-owned buildings to be certified through the USGBC's LEED rating system, the Green Building Initiative (GB1) Green Globes rating system, the Florida Green Building Coalition's (FGBC) standards, or another nationally recognized rating system. The legislation also authorized the Florida Climate Protection Act, mandating the DEP to develop a greenhouse gas (GHG) cap-and-trade program that could begin operation as soon as Jan. 1, 2010.
Although the events described above are unique in the Southeast, many other states nationwide are moving to adopt energy efficiency standards and reduce greenhouse gas emissions (most notably California). As Stephen Del Percio reports in another of the articles in this issue, "24 states and 90 local governments had adopted the U.S. Green Building Council's LEED green building standards, while 12 states had included the Green Building Initiative's Green Globes system in legislation" as of August 2007. These green certification programs are being adopted as standards of performance, in spite of the fact that there is very little information about how buildings designed and constructed in compliance with these programs actually perform.
PROJECT BACKGROUND
The building science aspect of energy-efficient construction is well understood while the most variable component of residential energy efficiency lies in occupant behavior and building maintenance. While the HERS rating system takes into account many of the factors that affect home energy use, it serves only as an indicator of actual energy use. This is a crucial and often overlooked point in many of the current discussions about green rating system products and/or certifications: they are not structured to actually measure the real energy consumption rates of the homes or developments that are given the certification. It is our hope that the current research work at the University of Florida, which significantly updates and expands detailed earlier work in the Gainesville area, will provide the necessary data and protocols for analysis in a fully transparent manner to aid the real development of the energy-efficient residential market. This paper provides only some of the initial indications of the data analysis, but they are of import for policymakers and developers. Fully detailed papers are being prepared for publication and should be available shortly.
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