GREEN RATING SYSTEMS & HISTORIC PRESERVATION
Green Rating Systems and preservation is a large topic and one that is well covered by Mike Jackson of the Illinois Historic Preservation Agency. Some of his references are listed below. OHP wishes to expand on the topic of Green Rating Systems and preservation in the future. Included for now is an illuminating report from the New Buildings Institute (NBI) that examines the performance over time of LEED certified buildings to determine if their energy use conforms to their design.
The All Green Ratings web site listed 26 green building rating systems as of July 2009. The USGBC web site refers to an even greater number but includes guidelines and materials rating systems.
For a discussion of the topic of Prescriptive versus Performance Standards Wayne Trusty’s article in the Journal of ASTM International is quite informative. In the abstract for this article he notes the following about the use of prescriptive measures: "prescriptive measures such as favoring building materials with recycled content do not always deliver the benefits they are widely assumed to have. They are means to an end and should not be treated as objectives in their own right. It is tempting to include prescriptive measures in a standard because they are easy to verify. But do we not then risk perpetuating points of view that, while deeply entrenched, do not contribute positively to actual building performance?”
A detailed discussion of house size relative to green ratings is provided in
Size Matters (a Lot):The Mistreatment of House Size in Green Home Rating Systems by Michael Horowitz. The author of this article was instrumental in the development of the Vermont Builds Greener formula on house size.
Build It Green is a non-profit membership organization whose mission is to promote healthy, energy- and resource-efficient building practices in California. They work with mainstream stakeholders in the housing industry to accelerate the adoption of green building practices. Build It Green has also created its own rating system for California, called GreenPoint Rated. They train their own inspectors, and maintain separate rating systems for new and existing construction. Historic and existing homes need a minimum of 50 points on the Existing Home scale in order to earn GreenPoint Rated certification.
Some cities, such as San Francisco, encourage historic homeowners to energy retrofit by adding points for the amount of character defining features retained, and discourage the teardown of historic homes by increasing the threshold of points required for certification if a historic building is demolished.
Build It Green has an innovative approach towards energy upgrading existing homes as well; homes that plan to remodel parts, such as a kitchen or bathroom, can plug into their "Elements" plan, which gives partial point credit that qualifies for both stand-alone certification and towards a complete upgrade of the home later.
LEED: The U.S. Green Building Council has several LEED (Leadership in Energy and Environmental Design) products, three of which are partly applicable towards historic buildings. LEED for Homes is a rating system that promotes the design and construction of high-performance green homes. It is not relevant for existing homes at this time. LEED for Existing Buildings: Operations and Maintenance is focused more on the commercial market and is concerned with fine tuning the maintenance and mechanical operations of a building, but could be applied towards a historic building. LEED for New Construction and Major Renovation can be applicable for major renovations of historic buildings. LEED for Neighborhood Development is a newer product that incorporates elements of community or district design into credits towards certification. USGBC and ASID (American Society of Interior Designers) together offer a home renovation guideline called ReGreen, which is not a rating system.
LEED has typically not been a product that is preservation-usable; however efforts are ongoing to work with USGBC to make their products more inclusive
The Living Building Challenge is one of the newest green rating systems and is attempting to move past the current systems and position itself as a “new and better approach to green.” It is still very much a tool based upon new construction, but does take a very different approach through the prerequisites rather than “trade offs” found in most existing green rating systems.
Architecture 2030 asserts that buildings are the major source of global demand for energy and materials that produce by-product greenhouse gases (GHG). Slowing the growth rate of GHG emissions and then reversing it is the key to addressing climate change and keeping global average temperature below 2°C above pre-industrial levels.
The Architecture 2030 Challenge asks the global architecture and building community to adopt the following targets:
• All new buildings, developments and major renovations shall be designed to meet a fossil fuel, GHG-emitting, energy consumption performance standard of 60% below the regional (or country) average for that building type.
• At a minimum, an equal amount of existing building area shall be renovated annually to meet a fossil fuel, GHG-emitting, energy consumption performance standard of 60% of the regional (or country) average for that building type.
The fossil fuel reduction standard for all new buildings and major renovations shall be increased to:
• 70% in 2015
• 80% in 2020
• 90% in 2025
• Carbon-neutral in 2030 (using no fossil fuel GHG emitting energy to operate).
These targets may be accomplished by implementing innovative sustainable design strategies, generating on-site renewable power and/or purchasing (20% maximum) renewable energy.