Page 169 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

LEED Ener gy and Atmospher e 147

document compliance with this prerequisite. For projects pursuing points under EA Credit 1,
the computer simulation model may be used to confirm satisfaction of this prerequisite. If a
local code has demonstrated quantitative and textual equivalence following, at a minimum,
the U.S. Department of Energy standard process for commercial energy code determination,
then it may be used to satisfy this prerequisite in lieu of ASHRAE 90.1-2004. Details on the
DOE process for commercial energy code determination can be found at www.energycodes.
gov/implement/determinations_com.stm.

USGBC Rating System LEED 2009
This prerequisite has been substantially changed in LEED-NC 2009 and is now similar to
the first few points in EAc1, Optimize Energy Performance from LEED-NC 2.2. Refer to the
three options and calculation pathways in the updated LEED-NC 2009 EAc1 for detailed
calculations. A summary of the requirements are outlined in Table 4.0.0.
Option 1 for EAp2 in LEED 2009 is based on a whole building energy simulation and
requires a 10 percent improvement in the proposed building performance for new buildings
and a 5 percent improvement for major renovations to existing buildings based on Appendix G
of ASHRAE Standard 90.1-2007 (with errata but without addenda). All the energy costs
associated with the project must be included, with the default process energy costs assumed
at 25 percent of the total energy costs for the baseline building similar to the LEED 2.2 EAc1
requirements. The process energy remains at this default value for the design case, except
if the team uses the exceptional calculation method (ECM) in Appendix G to document
applicable process energy reductions. The process energy cost items include office and
general miscellaneous equipment, computers, elevators and escalators, kitchen cooking
and refrigeration, laundry washing and drying, lighting exempt from the lighting power
allowance such as medical equipment lighting, etc. The regulated (or non-process) energy
is the main focus of the energy reduction. It includes interior, parking, facade or exterior
lighting (with exceptions), heating, ventilation and air conditioning (HVAC) (such as for
space heating and cooling, fans, pumps, toilet exhaust, parking garage ventilation, kitchen
hood exhaust) and service water heating for domestic use or heating. Option 1 in LEED
2009 EAp2 also requires compliance with mandatory provisions listed in Sections 5.4, 6.4,
7.4, 8.4, 9.4, 10.4 in Standard 90.1-2007 (with errata but without addenda). The prescriptive
requirements in Sections 5.5, 6.5, 7.5, and 9.5 of ASHRAE Standard 90.1-2007 are not
specifically noted in LEED 2009 EAp2, but are referred to in the LEED 2009 reference guide
and therefore compliance is implied. (There is also an alternative code that may be used for
California projects based on California Title 24-2005, Part 6 for Option 1.)
Option 2 for LEED 2009 EAp2 is titled the Prescriptive Compliance Path: ASHRAE
Advanced Energy Design Guide, while Option 3 is titled Prescriptive Compliance Path:
Advanced Buildings Core Performance (TM) Guide based on a guide developed by the
New Buildings Institute (NBI). Options 2 and 3 both have restrictions on the size of the

project and also have specific requirements for certain uses. Summaries of Options 2 and
3 for LEED 2009 EAp2 are listed in Table 4.0.3.

Calculations and Considerations LEED 2009
This prerequisite uses the ASHRAE/IESNA 90.1-2007: Energy Standard for Buildings
except Low-Rise Residential. This standard was sponsored by the American Society of
Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the Illuminating
Engineering Society of North America (IESNA) under an American National Standards
Institute (ANSI) process. It sets minimum energy requirements and energy efficiency
requirements. It does not apply to buildings that use neither electricity nor fossil fuel,
manufactured houses, or portions of buildings that use energy primarily for industrial,
manufacturing, or commercial processes.