Little by little in the analysis of the benefits of the building new elements are being incorporated where it is no longer just about to assess energy consumption, water use or cost economic. Increasingly, and this is good news, it is considered the environmental impact that buildings produce both in its construction and in its phase of use or end of life.
This methodology is called Life Cycle Assessment (LCA) of the buildings and it is beginning to be sufficiently “matures” to be able to start using it at the building level as a tool to detect how they can influence different options: conception, design, construction, use... in the buildings in the resulting environmental impact for the whole of the building.
Most certifications that have for sustainability ( LEED / BREEAM / GREEN /…) try, with more or less success, address this problem, but, they often do so based on a biased selection of some set of materials to which without prior justification are considered “responsible” for the impacts of the buildings and those who are required benefits environmental factors that do not always lead to obtaining a building with less impact.
Among the materials that are systematically considered "suspected" of causing high impacts on the building are usually consider; insulations, coatings, paintings … but too often they are “forgotten” the impacts caused by other families of materials such as; facilities, structure, foundation …
In previous articles it was already shown that the environmental impact derived from the products of construction only made sense when put in the context of building and that the environmental impact caused by the insulators is more than offset by the reduction in impacts derived from the use of energy in the useful life of the building.
Let's get started! But first, we have to check what programs we are going to use for the calculations.
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In this article we will try to carry out an LCA exercise on a building and identify for this specific case that families of construction elements or phases of use of the building cause greater environmental impact.
We will use the programs CYPETHERM HE PLUS (See software HERE) to perform the estimation of energy consumption and ELODIE by CYPE (See software HERE) for carry out the Life Cycle Assessment of the model.
The BIM methodology used by these computer tools easily allows, once the model of the building is built, carry out the different calculations with minimal effort part of the user.
Someone might object that the LCA carried out by ELODIE by CYPE uses the methodology prescribed in France and which, in Consequently, environmental impacts could be “biased” by this geographical environment, but in a globalized world.
Does anyone believe that the impacts derived from the products are substantially different in Spain than in France? when in fact, in France, they are very often used products that come from Spanish manufactures.
For this exercise, we will use a home detached house located in a climate like that of Barcelona. In the attached graphs you can see different “views” of the building:
The construction of the building is “conventional” with resistant walls made of brick, forged with joists and vaults, pavements of concrete, covered with tiles on a wooden structure.
A partition based on laminated gypsum board, insulators glass wool on walls and roof (200 mm) and extruded polystyrene on floors (100mm), mixed carpentry aluminum and wood with double glazing, pavements of ceramics, conventional plastic paint, installations of plumbing, electricity and communications,…
The results as offered directly by ELODIE by CYPE are suitable for analyzing the different impacts produced in each of the stages of the cycle of life .
Or also to evaluate the contribution of a chapter or set of chapters of the LCA of the building.
Or even a specific material used in an element constructive.
But they are not well adapted (at the moment) to analyze directly the impact of families of materials, for example, insulators, which can be used in different elements constructive.
To do this, the ELODIE by CYPE program has the option to export the results to a file that can be read by the ELODIEweb calculation engine that allows obtain the detailed results (In Excel table) of all and each of the components that have been considered in the construction of the model.
In our case we have identified each component with the family of materials that we want to evaluate to finally Obtain the added values of each one. We have considered the following component “families”:
| Insulators | Structure |
| Masonry | Waterproofing |
| Carpentry | Facilities |
| Water Consumption | Flooring |
| Energy Consumption | Painting |
| Work Execution | PYL partitions |
| Wood Structure | Texas |
We proceed to analyze for each impact indicator environmental the contribution of each “family” to the total of the Cycle of Life of the building and we present it through graphs to a better understanding:
It is clearly appreciated that, for each environmental impact exists, one or more families of materials that happen to be the “dominant” ones and that, between one impact or another, the hierarchy of those “responsible” for the environmental impact are different.
Therefore, in each case, according to the impact that you want to optimize you should act on different options ; sometimes modify the construction or constructive typology , sometimes reducing the energy or water used in the operation phase of the building.
The analysis can also be carried out from a perspective multicriteria placing in a single graph those impacts that are considered most important.
This type of analysis allows us to identify which groups of materials or of operation contribute something relevant from a environmental impact point of view either because they are the greatest contributors to a given impact or that present high values of contribution to
various impacts.
It is appreciated as the “ INSULATION family ” very frequently accused of being a large contributor to environmental impacts, in reality, it is very insignificant from a point of view of the impacts caused. while it is a great benefactor thanks to the reduction of energy consumed.
The contribution of a family of products can be shown through graphics that allow detecting about what parameters a family of products cause the greatest impacts .
It can be seen that for the insulating family the impacts are all very small . the highs less than 2% of the total stroke of the building so there is no point in trying to reduce the impact environment of a complete building.
Similarly, we see that energy consumption presents high environmental impacts in several indicators above 30% such as; energy use Primary, Air Pollution, Depletion of Fossil Resources fuels, destruction of the ozone layer and higher than 10% for the Greenhouse Effect.
