From the website: "The Advanced Energy Design Guide series provides a sensible approach to easily achieve advanced levels of energy savings without having to resort to detailed calculations or analysis.
The four-color Guides offer contractors and designers the tools, including recommendations for practical products and off-the-shelf technology, needed for achieving a 50% energy savings compared to buildings that meet the minimum requirements of ANSI/ASHRAE/IESNA Standard 90.1-2004.
The energy savings target of 50% is the first step in the process toward achieving a net-zero energy building, which is defined as a building that, on an annual basis, draws from outside resources equal or less energy than it provides using on-site renewable energy sources.
These Guides have been developed through the collaboration of ASHRAE, the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), and the U.S. Green Building Council (USGBC), with support from the Department of Energy (DOE), to help meet all of an owner's energy performance requirements.
In an effort to promote building energy efficiency, ASHRAE and its partners have made these Guides available for download (PDF) at no charge."
Look at Chapter 5: How to Implement Recommendations/ EN 5 (envelopes) Walls- Mass (climate zones-all):
"The greatest advantages of mass can be obtained when insulation is placed on its exterior. In this case, the mass absorbs heat from the interior spaces that is later released in the evenings when the buildings are not occupied.
The thermal mass of a building (typically contained in the building envelope) absorbs heat during the day and reduces the magnitude of indoor air temperature swings, reduces peak cooling loads, and transfers some of the absorbed heat into the night hours.
The cooling load can then be covered by passive cooling techniques (natural ventilation) when the outdoor conditions are more favorable.
An unoccupied building can also be precooled during the night by natural or mechanical ventilation to reduce the cooling energy use.
This same effect reduces heating load as well.
Thermal mass also has a positive effect on thermal comfort. High- mass buildings attenuate interior air and wall temperature variations and sustain a stable overall thermal environment. This increases thermal comfort, particularly during mild seasons (spring and fall), during large air temperature changes (high solar gain), and in areas with large day-night temperature swings."
Thanks for keeping in mind the first rule of energy efficient design: reduce the building energy load through passive means.
NRG walls and hollow core floor slabs ( http://www.termobuild.com/ ) are low cost passive systems that can make big contributions to carbon reduction.