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Life Cycle Assessments

Life cycle assessments should never be used, tendered or used in building balance sheets without reflection, otherwise you may quickly end up with a completely unrealistic assessment of the environmental situation that has little to do with real conditions.


Contractors should also be aware that life cycle assessments do not improve the environment, because they only describe a condition, like a list of contents on packaging. The advertiser would then have to classify himself whether this is a good condition or not, which is usually not possible in this way.  



There are different approaches to assessing the environmental impact of products. They differed in how they proceeded.


Essentially, the following should be mentioned here: environmental labels (environmental label type I, ISO 14024) and life cycle assessments or environmental product declarations (environmental label type III, ISO 14025).

Environmental labels evaluate products based on criteria and monitor compliance with the criteria set. They aim to comply with certain environmental impacts (e.g. sustainable forest management, climate, health, etc.). Environmental labels achieve real environmental improvement.

By definition, environmental product declarations do not represent an evaluation of products, but only documentation. They do not have the primary goal of simplifying a procurement or purchase decision. While broader in approach and parameters covered, they have a number of limitations and problems. What is particularly important, however, is that they are inherently systemic and are not designed to achieve a real, direct improvement in the environment.  

What should municipal procurement and property developers consider when using life cycle assessment data?

In general, an important goal in the further development of life cycle assessments would be that the users of life cycle assessments, such as the municipalities, not only simply have to take note of the environmental data of an EPD mentioned here, but also be able to understand them. This is the only way you could put the data mentioned here into a real comparison and only then could you achieve a real improvement in the environment based on a procurement decision based on life cycle assessment data.

The users of life cycle assessments such as municipal procurement officers and planners should also be able to understand how the figures given here came about. Otherwise there is a risk that, for example, environmental data from wood products whose material flow begins in the forest will be compared with environmental data from plastic products whose material flow possibly begins in the granulate silo in the port of Hamburg (and not with oil production), or something similar.  

As a buyer, also consider the following:

  • Experts of a life cycle assessment confirm with their signature under an EPD that the life cycle assessment was implemented in accordance with ISO and not whether the data, assumptions, calculations and statements contained are plausible and also not whether they depict realistic upstream chains (for an expert this is the input variables does not exist or does not come from the respective industry is not even possible).

  • This applies above all to the transports in the upstream chains, because these are usually calculated with standard data sets, which as a rule underestimate the transports in the entire upstream chains.

  • If you want to achieve a real environmental impact with your procurement, you cannot simply use life cycle assessment data from an EPD that was created for German or at most Central European conditions (like most classic life cycle assessments up to now) if you do not know where the product comes from procure.

  • An EPD is not a proof of origin for a product that you advertise.  

  • However, knowing the origin would be extremely important for assessing the environmental impact of a product. As a system immanent, life cycle assessments do NOT record the life cycle phase A4 (gate to customer), i.e. the transport from the last processing step to the place of use of the product. For the real environmental impact, however, it is extremely important whether, for example, the plate you order comes from Central Europe or has come a long way from China.



Difficulties in classifying individual life cycle assessments for real procurement processes  


First of all, procurers should know that in classic life cycle assessments, only quantitative, quantity-related aspects are inherent in the system and not qualitative aspects. However, such qualitative aspects can be systemically much more important for the real environmental impact of a product than quantitative aspects.

The typical bare numbers in classic life cycle assessments are also not suitable for illustrating the importance of the environmental impact and making it tangible for tenderers in municipalities, building authorities and their planners. A layman (and this includes all people except the creator of the life cycle assessment or people who have not been dealing with life cycle assessments for a long time) cannot judge whether, for example, 10.111111 kg of CO2 equivalent is a lot and poses a problem or not.


Users need a system that compares values directly in order to be able to make a direct decision in practice for or against a product from an environmental point of view.


But even when comparing different life cycle assessment data, this is not really clear. For example, what does a value of 10.1111 compare to 13.11222, except that one is slightly higher and the other is slightly lower. But are there also values of 1333.1111 and then what does that mean?


In addition, many environmental impacts in classic life cycle assessments are so low in terms of pure numbers that every user asks: “Does that even matter? For example, what does a value for ADP of 0.000045678 kg Sb equivalent mean?


On the other hand, other very important environmental impacts, such as loss of biodiversity, felling in primary forests, accidents, hazardous waste in the extraction of raw materials such as red mud in the extraction of bauxite or the like and other environmental pollution caused by the extraction of raw materials are not part of life cycle assessments, even if they can be far more significant as eg acidification or eutrophication potential.



Do not use life cycle assessments without thinking


Why aren't classic life cycle assessments sufficient to enable a comprehensive description of the eco-social impact of a product?

As part of various studies and projects, the publisher of this platform has repeatedly analyzed a wide variety of existing life cycle assessments and environmental product declarations, especially for construction products, in an attempt to identify reliable and comparable sources of information on environmental impacts.


There were always a number of difficulties that arose  have also been confirmed in numerous discussions with environmental assessors and experts.


(1) Aggregation of values "A1-A3" must be considered "black box datasets".


In life cycle assessments, the last production step is usually dealt with under life cycle phase "A3", while all other production steps of the upstream chains are usually dealt with according to the life cycle assessment principles  are subsumed in the life cycle section "A1". The problem with many life cycle assessments is that the life cycle phases A1, A2 and A3 are combined (A1 - A3) and not shown separately. With regard to the data sets used, the assumptions made and the calculation steps applied, they represent a black box for users of the data. A user cannot track the balance sheet data separately for A1, A2 and A3. Comparing "black box data" with other data is difficult if not impossible.


(2) Often unclear balance area and lack of verifiability and comparability  

Even if generic EPDs generally state that all upstream chains have been taken into account, it is not possible for the user or the tenderer to understand whether and how exactly all upstream chains have been taken into account.


Classic life cycle assessments are usually created with computer programs that use standard data sets for the calculation. Due to a lack of other available data, these standard data sets are often used for calculations with the program, but the users of the computer programs usually no longer check their plausibility (which they usually could not do at all). Such standard data sets come from various databases, some of which are public and some of which are subject to a fee, such as Ecoinvent, GEMIS 4.4, PROBAS, the Umberto library, the US life cycle inventory database and numerous other institute databases.

The assumptions and calculation steps in life cycle assessments cannot be checked without knowing which data was used for the calculations in the programs. The calculation methods are a "black box" for the user.


By default, the EDP output documents for each life cycle assessment say "all upstream chains" were taken into account", but users can no longer verify this claim based on the information in the EPD documents. For this reason, many life cycle assessment data cannot simply be compared with one another. The application to other contexts or, for example, other, more practical, pre-chains is difficult or impossible.

(3) Problems with standard electricity and heat datasets

Life cycle assessments are essentially based on the consumption of electricity and heat in production. As a rule, life cycle assessments use standard data sets for calculating the environmental impact of electricity and heat consumption, which are based on data on the electricity mix of the respective country of the last production step.


Many life cycle assessments are based on these standard data sets for electricity, thermal energy and process steam. This means that regardless of where the pre-products were produced, if the last production location is Germany, for example, the "Germany electricity mix" is used. This is also logical, since a life cycle assessment cannot usually make any statements about the real material flow and the origin of the preliminary products.


Many German life cycle assessments also use other electricity mixes. Data sets that indicate average conditions in Europe (EU-28 or EU-15) are also common. Depending on the data set, a life cycle assessment can be significantly better or worse, with the same consumption of electricity and heat. But that also means that every company that stands out here in reality, for example by purchasing green electricity, or electricity from its own solar system or heat from its own wood waste or other, cannot or hardly stand out here, unless it won't standard data sets are simply used and these differences are included in the life cycle assessment and presented transparently.

(4) Underestimation of transports

In standard life cycle assessments, the life cycle phase A1 often means that the entire environmental footprint of the preliminary products is included by the computer programs used and not just the extraction of the primary raw material, as one would assume based on the description "A1 = raw material extraction".


Due to the fact that when creating an EPD, calculations are made with standard computer programs (e.g. Gabi Software from PE International) and with standard data sets for the preliminary processes and many EPDs summarize the life cycle phases A1-A3, which is also the case with standard data sets of preliminary products, the environmental impacts of these primary products are usually assigned to life cycle phase A1. If, for example, an EPD is created for the manufacture of window frames and PVC granulate is defined as the pre-product, the entire environmental impact of the manufacture of PVC granulate (A1-A3) is summarized and calculated by the computer program in the window EPD for life cycle phase A1. Therefore , A1 cannot be shown separately from the classic life cycle assessment data.


In classic life cycle assessments, standard data sets are often used for transport calculations. An analysis of around 70 EPD construction products that identify A1, A2 and A3 separately (Bruckner and Strohmeier, 2019) showed that transport distances of 50 - 500 km are usually assumed here, regardless of the material, which corresponds to real transports in the entire material flow of the upstream chains of many products has nothing to do. For example, some of the raw materials or preliminary products of the analyzed EPDs do not occur in the production country under consideration (e.g. bauxite). This means that the aspect of transport in the upstream chains of most products with life cycle assessment data is very much underestimated, which is inherent in the system.


In general, one can only assume that all transports have been taken into account if the transport distances (km) and the transport load (t*km) including the allocation steps are transparent and comprehensible in a life cycle assessment.  

(5) Existing generic data mostly apply to German production conditions and may not simply be transferred to other countries

Generic "black box data records" relevant to German production conditions and created in life cycle assessments cannot simply be transferred to production in other countries, because then one would then assume that production there is just as energy, water and resource efficient as in Germany, which cannot be assumed automatically. Life cycle assessment data for building materials or components produced in Poland, for example, would have to calculate with twice as high CO2 values as with production in Germany.


(6) Reusability hardly plays a role in life cycle assessments and if so, it should be viewed critically

In life cycle assessments, transport to the disposal company is almost always based on standard data sets, which usually assume a disposal route of 50 - 100 km. That has nothing to do with the reality in today's at least European market for residues and waste. The data also significantly underestimates the transports in this life cycle phase.

The purely theoretical data for the disposal route in studies and databases is between 0.43 - 0.72 kg CO2-eqv/m3 for almost all building material groups. These theoretical values have no meaning in the CO2 balance. In reality, however, this can be completely different.


In addition, it is unclear what the ways and options for subsequent use are for a building product that is installed today and will be used in 50 or more years. Any accounting of environmental values for subsequent use is speculative. Therefore go  the EN standard here in the life cycle phase "C" (path to subsequent use) from "scenarios".


For the  Life cycle phase "D" after-use, standard data sets are usually used in life cycle assessments, which cannot be product-specific at all.


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