Life Cycle Assessment and Environmental Product Declarations

LCA was developed as a useful methodology for the objective, methodical, systematic and scientific analysis of the different potential environmental impacts associated with each of the stages of a product's complete life cycle, from cradle to grave.

This methodology has four phases:

PHASE 1 - Definition of objectives and scope

This is the phase where the reasons and the context in which the LCA will take place are established. Issues to be defined include:

  1. Functional Unit: measure of the function of a product to which all system data will refer.
  2. System boundary: the components and processes that make up the product system will be specified, delimiting which ones are covered and which ones are left out.
  3. Assignment rules: for when several functions or co-products are developed.
  4. Impact categories: indicate which ones are to be calculated and the calculation methodology.
  5. Quality of the data: taking into account temporal, geographical and technological coverage.
PHASE 2 - Life Cycle Inventory.

This is the data collection phase, where all the input flows (consumption of materials and energy) and output flows (waste emitted into the air, water and soil) of the different processes that are part of the system are studied.
In this phase, the guidelines set out in the previous phase regarding allocation rules and data quality requirements are followed.

PHASE 3 - Life Cycle Impact Assessment.

In this phase the classification and characterisation of the inventory results is carried out, with standardisation and weighting as an optional step.

  1. Classification: All inputs and outputs should be classified according to the type of impact they may have on the environment in different impact categories. In general, there are two types:
    1. Midpoint: those impact categories that focus on the amount of resources consumed and waste generated per unit of output,
    2. Endpoint: those impact categories that address the consequences of interventions on the environment.
  2. Characterisation: using characterisation factors, each input and output is transformed by calculating the contribution of each, relative to the impact category considered (e.g. CO2 equivalent emissions).
  3. Normalisation and weighting: these are optional calculations that help the interpretation of the result. Normalisation indicates the relative importance of the environmental impact in relation to a given geographical area. This normalised impact can then be multiplied by weighting factors and the partial results summed to produce a single overall environmental impact indicator.
PHASE 4 - Interpretation.

This phase should include identification of significant issues, assessment, conclusions and recommendations.

Fases del ACV. Fuente Proyecto SOFIAS

LCA phases. Source SOFIAS Project

Starting from the four stages of the trace structure, the life cycle inventory collection phase involves a great deal of effort on the part of the developer. The majority of environmental databases are payment and the user has to decide which one to use. According to the information provided, there are three types of databases:

  1. Metadatabase or simple pre-established processes (collection of inputs and outputs to the study system). Generally embedded in the information and can be edited by the user in the tools (e.g. Ecoinvent, Gabi, ELCD, etc.).
  2. EPD databases (LCA results following UNE-EN 15804:2012+A2:2020 and the corresponding Product Category Rules (CPR) for the result of EPD, e.g. Global EPD, IBU, ÖKOBAUDAT, etc.)
  3. Other environmental databases (collect relevant information, but cannot be used to calculate the LCA, e.g. Embodied Carbon - The ICE Database, BEDEC Bank, Sustainable Construction Agenda Database, CEDEX Waste Catalogue, etc.).

Quantification and assessment

Life Cycle Assessment (LCA) helps to identify the impacts generated on the environment. In buildings, quantification of these impacts can be used to assess the decisions made in the design of the building. An assessment can be made using a calculation tool, consultation with an expert or a checklist review.

The review of the building by means of a specific list of milestones (Check List), brings with it subjective evaluations of the results according to the scores of the person who configures it. They are not comparative, if they are not of identical origin, but they do provide a scale of positioning within the internal functioning of the building.

There are several building environmental assessment systems on the market, such as GBC- GBTool (Canada), VERDE (Spain), BREEAM (Great Britain), ESCALE (France), Eco/Quantum (Netherlands), EcoEffect (Sweden), LEED (USA), ENVEST (Great Britain), CASBEE (Japan), etc. Each of these certification systems generates its own software tool and trains its assessors. An assessor carries out the assessment of the building according to the criteria and analyses generated. This results in a rating on a certain scale. The greatest competition between the different assessment systems is at the level of advertising. Their expansion depends on the owner's demand to rate his building using such a system.

And if we finally opt for a tool to calculate the impacts generated, we can take into account a multitude of data and parameters that enter into account. There are generic LCA calculation tools, and there are also those specific to the construction sector. Some considerations to take into account are: the functioning of the database; the origin, quality and extent of the data; the possibility of editing existing data; the possibility of importing other databases; the ease of use of the system; the use of different impact assessment methods; and the versatility of visualisation and obtaining the results.

The environmental assessment of the building by LCA calculation tools, as we have seen, has two key considerations: the database and the operability of the system. Currently, the databases with the highest number and quality of data correspond to paid tools, and this is their main value. The data are generally not very geographically representative, which penalises the quality of the results. And in other cases, we start from a lack of data, which makes it difficult to calculate. All of this has to be resolved with databases that respond to pre-established, importable criteria and standards, and with qualification of the quality of the data used.


LCA quantification processes (Source: Authors' own creation)

EPD, PCR and EPD Programme

ISO 14025 defines Environmental Product Declarations or Type III ecolabels as a "statement that provides quantified environmental data using predetermined parameters and, where appropriate, additional environmental information".

The objective of an EPD is the same as that of other ecolabels, i.e. to encourage the demand for and production of products that have a lower impact on the environment through the communication of verifiable and accurate information that stimulates continuous environmental improvement among market players. Since any product can be subject to an EPD without this implying that it has a better than average environmental performance, the desiredstimulation of continuous improvement in the market is promoted in this case through comparison between products. For this comparison to be done correctly and to ensure that the information contained in different EPDs is not misleading, it is necessary that the same rules are applied when obtaining them. In this respect, the default parameters contained in an EPD are based on the ISO 14040 and ISO 14044 series of LCA standards, as well as on the Product Category Rules (PCR) applicable to the product in question.

The CPR specifies specific aspects for the development of a EPD, individualising rules and requirements specific to the product group to which it refers. They determine aspects such as the objective and scope of the LCA, the life cycle phases to be included, the parameters to be covered and the manner of calculation, as well as possible omissions and the preparation of additional environmental information. UNE-EN 15804:2012+A2:2020 aims to "establish the basic PCR for type III environmental declarations for any construction product and service."

Types of EPDs according to the life cycle stages covered, together with life cycle stages and modules for the assessment of construction works. Source: UNE-EN 15804:2012+A2:2020.

Types of EPDs according to the life cycle stages covered, together with life cycle stages and modules for the assessment of construction works. Source: UNE-EN 15804:2012+A2:2020.

Regarding the quantitative information reflected in the EPD, UNE-EN 15804:2012+A2:2020 addresses a limited number of pre-defined quantifiable environmental impacts and life cycle indicators:

norma UNE-EN 15804:2012+A2:2020

ISO 14025 defines the requirements for EPD to provide a reliable, relevant, transparent, transparent, comparable and verifiable environmental profile based on LCA information and through specific rules for each product family according to CPRs. These are the EPDs programme, "body or bodies that carry out an EPD programme", containing a set of operational and regulatory compliant rules. Sometimes, in the absence of CPRs, they may develop their own. In addition to being responsible for the verification and enforcement of all rules. Establish clear and transparent procedures for review of CPRs and EPD.