5.1 This practice provides criteria that building design teams shall use to compare the environmental impacts associated with a reference building design and a final building design, including additions to existing buildings where applicable.

5.2 This practice deals specifically with material selection for initial construction, including associated maintenance and replacement cycles over an assumed service life, taking operating energy use into account if required or explicitly allowed under the applicable code, standard, or rating system.

1.1 This practice provides criteria to be applied irrespective of the assessment (LCA) tool that is used when LCA is undertaken at the whole building level to compare a final whole building design to a reference building design.

1.2 The purpose of this practice is to support the use of whole building Life Cycle Assessment (LCA) in building codes, standards, and building rating systems by ensuring that comparative assessments of final whole building designs relative to reference building designs take account of the relevant building features, life cycle stages, and related activities in similar fashion for both the reference and final building designs of the same building.

1.3 The criteria do not deal with building occupant behavior, possible future changes in building function, building rehabilitation or retrofit, or other matters that cannot be foreseen or reasonably estimated at the design or permitting stage, or both where this practice applies.

1.4 Only environmental impacts and aspects of sustainability are addressed in this practice. The social and economic impacts and aspects of sustainability are not addressed in this practice.

1.5 This practice does not deal with basic LCA methodology, calculation methods or related matters that are covered in cited international standards.

1.6 This practice does not supersede or modify existing ISO standards for the application of LCA at the product level, nor does it address any of the following related applications:

1.6.1 Aggregation of building products Environmental Product Declarations (EPD) at the whole building level;

1.6.2 Rules for applying EPDs in a building code, standard, or rating system; and

1.6.3 Comparability of building product EPDs.

Note 1: ISO 14025 and ISO 21930 provide guidance on use and comparability of building products EPDs.

1.7 This practice does not specify the impact categories or sustainability aspects to be addressed in building codes, standards, or building rating systems and users of this practice conform to the impact category requirements specified in the applicable code, standard, or rating system.

1.8 The text of this standard contains notes that provide explanatory material. These notes shall not be considered as requirements of the standard.

1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.