G-05 Scope definition for building and product LCA

Aspect G-05 Scope definition for building and product LCA
Description

According to [ISO 14040], [ISO 14044], and the ILCD Handbook, the scope definition of a study is the step where the main requirements related to methodology, quality, reporting and review in accordance with the goal of the study (i.e. based on the reasons for the study), the decision context, the intended applications, and the addressees of the results [ILCD 2010c] are stated. Examples of requirements include the function, functional unit and reference flow definitions, derivation of system boundaries, and cut-off criteria (completeness).

How can the practitioner set up the scope of the study? Are there special cases where the effort of scope definition can be simplified in regard to product or building LCAs?

Related study objective

 stand-alone LCA comparative assertion

Related study phase

goal and scope definition inventory analysis (LCI) impact assessment (LCIA) interpretation reporting

Relevant for

new buildings existing buildings construction products screening LCA simplified LCA complete LCA
Provisions

The scope definition of a study should be defined according to the context and the intended use of the assessment.

The documentation should also be in line with ISO 14044, EN 15978 and EN 15804.

Rules from:
EN 15978:

6 Purpose of the assessment

7 Specification of the object of assessment

EN 15804:

6.2 Life cycle stages and their information modules to be included

6.3 Calculation rules for the LCA

ILCD:

6 Scope definition – what to analyse and how

Provisions 6.2.1 Consistency of methods, assumptions, and data

Provisions 6.2.2 Reproducibility

Provisions 6.3 Types of LCA deliverables and intended applications

Provisions 6.4 Function, functional unit, and reference flow

Provisions 6.5.4 LCI modelling provisions for situations A, B and C

Provisions 6.6 Deriving system boundaries and cut-off criteria (completeness)

Provisions 6.7 Preparing the basis for the impact assessment

Provisions 6.8.2 Technological representativeness

Provisions 6.8.3 Geographical representativeness

Provisions 6.8.4 Time-related representativeness

Provisions 6.9 Types, quality and sources of required data and information

Provisions 6.10 Comparison between systems

Provisions 6.11 Identifying critical review needs

Provisions 6.12 Planning reporting

ISO 14044:

4.2 Goal and scope definition

Guidance

1) General guidance for product or building LCA studies

This step is closely linked to the goal definition. It is recommended that the LCA practitioner does not start from ‘zero’, but rather follows EN 15804 and EN 15978 if the scope definition within these standards is relevant for the context of the study. If not, it is recommended that the ILCD guidance on how to define the different aspects of the scope be used (see the rules from ILCD).

2) Practical guidance for product and building LCA studies according to the scope definition of EN 15804/EN 15978

The scope of the study defines the various contributors to include in the LCA study, such as the building products (Modules A, B, C, D), construction site (Module A5), energy consumption (Module B6), water consumption (Module B7), and transport of people (during the use phase).

The inclusion of any module depends on the goal definition, the stage of the project, and the LCA practitioner. Generally speaking, all the provisions for scope definition in EN 15804 and EN 15978 should be applied.

3) Predefined scope of product and building LCA studies according to EeBGuide study types

The definition of the scope of a study within the context of this guidance is also broadly predefined through the study type (screening, simplified or complete LCA). Provisions for aspects such as the completeness of the assessment (e.g. adapted calculation rules, system boundaries and cut-off-criteria), data representativeness and type (e.g. use of default values), documentation and communication help the definition of the scope. The reporting templates of the EeBGuide also help regarding documentation of the goal and scope of an LCA study.


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