Page 174 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

152 Cha pte r F o u r

4.1 EA Credit 1: Optimize Energy Performance
The intention of this credit is to give credit for minimizing energy usage on-site, and also
to encourage minimizing the use of off-site power and other off-site energy sources.

USGBC Rating System
LEED-NC 2.2 lists the Intent for EAc1 as follows, which is essentially identical to the
LEED 2009 Intent. The requirements from LEED 2.2 have been updated to refl ect the
LEED 2009 changes.

Intent
Achieve increasing levels of energy performance above the baseline in the prerequisite
standard to reduce environmental and economic impacts associated with excessive energy
use.

Requirements The requirements have changed significantly with the conversion to the

LEED 2009 version, with the most significant change being the point values given, and
minimum energy reductions from the baseline now part of the prerequisite EAp2. The
baseline standard is now the 2007 version of ASHRAE/IESNA Standard 90.1 Appendix G
(with errata but without addenda) for Option 1. The 2009 version allows the project team to
select one of the three compliance path options described. Project teams documenting
achievement using any of the three options are assumed to be in compliance with EA
Prerequisite 2.
OPTION 1 — WHOLE BUILDING ENERGY SIMULATION
This option requires that the project team demonstrate a percentage improvement in the
proposed building performance rating compared to the baseline building performance
rating by a whole building project simulation using the Building Performance Rating
Method in Appendix G of the Standard. The points available for EA credit 1 for both the 2.2
and the 2009 versions of LEED New Construction and Major Renovations are displayed in
Table 4.1.1 with the percent reduction from a baseline energy cost noted for each.
Appendix G requires that the energy analysis done for the Building Performance Rating
Method include ALL of the energy costs within and associated with the building project. To
achieve points using this credit, the proposed design must also adhere to the requirements
as listed in EAp2 which include that the project:
• Must comply with the mandatory provisions (Sections 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4);
• Must include all the energy costs within and associated with the building project;
and
• Must be compared against a baseline building that complies with Appendix G. The
default process energy cost is 25% of the total energy cost for the baseline building.
For buildings where the process energy cost is less than 25% of the baseline
building energy cost, the LEED submittal must include supporting documentation
substantiating that process energy inputs are appropriate. Process energy and
regulated (nonprocess) energy are as defined in EAp2 and process loads shall be
identical for both the baseline building performance rating and for the proposed
building performance rating. Project teams may follow the Exceptional Calculation
Method in ASHRAE 90.1 2007 to document measures that reduce process loads. As in
LEED 2.2, documentation of process load energy savings shall include a list of the
assumptions made for both the base and proposed design, and theoretical or empirical
information supporting these assumptions. Projects in California may again use the
Title 24-2005, Part 6 standard in place of the ASHRAE standard as stated in EAp2 for
EAc1 Option 1.