Help the development of the site, sharing the article with friends!
Environmental impact of a building
Little by little, in the analysis of the building's performance, new elements are incorporated where it is no longer just a matter of evaluating energy consumption, water use or economic cost. Increasingly, and it 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 It is called Life Cycle Analysis (LCA) of buildings and it is beginning to be sufficiently “mature” to be able to start using it at the building level as a tool to detect how different options can influence: conception, design, construction, use … of buildings in the resulting environmental impact for the whole of the edifice.
most of certifications that are aimed at sustainability (LEED / BREEAM / GREEN/…) Try, with more or less success, to tackle this problem, but they frequently do so based on a biased selection of some set of materials that, without prior justification, are considered “responsible” for the impacts of buildings and that environmental performance is required of them that do not always lead to a building with less impact.
Among the materials that are systematically considered "suspicious" of causing high impacts on the building are usually considered; insulators, coatings, paints… But all too often the impacts caused by other families of materials such as; facilities, structure, foundation…
we seek to know which elements of a construction cause a greater environmental impact
In previous articles it was already shown that the environmental impact derived from construction products only made sense when put in a building context and that the environmental impact caused by insulation is more than offset by the reduction of environmental impacts derived from the use of energy in the useful life of the building.
We started! But first, we have to verify which programs we are going to use for the calculations.
What programs are we going to use
In this article we will try to carry out an LCA exercise on a building and identify for this specific case which families of construction elements or phases of use of the building cause the greatest environmental impact.
We will use the programs CYPETHERM HE PLUS (See software HERE) to perform the estimation of energy consumption Y ELODIE by CYPE (See software HERE) for perform the Life Cycle Analysis of the model.
The BIM methodology used by these computer tools allows easily, once the building model has been built, to carry out the different calculations with minimal effort on the part of the user.
once the model is built, with the BIM methodology used by these software it is much easier to perform the calculations
Someone could object that the LCA carried out by ELODIE by CYPE uses the methodology prescribed in France and that, consequently, the 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, products that come from Spanish manufactures are very often used.
Case study
For this exercise, we will use a isolated single-family home located in a climate like that of Barcelona. In the attached graphics you can see different "views" of the building:
The building construction is "conventional" with resistant brick masonry walls, slabs with joists and vaults, concrete slabs, covered with tiles on a wooden structure.
A partitions based on laminated plasterboard, glass wool insulation on walls and roof (200 mm) and extruded polystyrene on floors (100mm), mixed aluminum and wood carpentry with double glazing, ceramic flooring, conventional plastic paint , plumbing, electricity and communications installations, …
The results as directly offered by ELODIE by CYPE are suitable for analyze the different impacts produced in each of the stages of the life cycle.
Or also to evaluate the contribution of a chapter or set of chapters of the building's LCA.
Or even a specific material used in a construction element.
But they are not well adapted (at the moment) to directly analyze the impact of families of materials, for example, insulators, that can be used in different construction elements.
To do this, the program ELODIE by CYPE has the option of exporting the results to a file that can be read by the ELODIEweb calculation engine that allows obtaining detailed results (in an Excel table) of each and every one 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 wish to evaluate to finally obtain the added values of each one. We have considered the following component “families”:
| Insulators | Structure |
| Brickwork | Waterproofing |
| Carpentry | Facilities |
| Water Consumption | Pavements |
| Energy Consumption | Painting |
| Work Execution | PYL partitions |
| Structure Wood | Roof tiles |
Results
We proceed to analyze for each environmental impact indicator the contribution of each “family” to the total Life Cycle of the building and present it through graphs for a better understanding:
It is clearly appreciated that, for each environmental impact, there is one or more families of materials that turn out to be the “dominant” and that, between one impact or another, the ranking of those “responsible” for the environmental impact are different.
Therefore, in each case, depending on the impact that you want to optimize, you should act on different options; sometimes modify the construction or construction typology, sometimes reducing energy or water used in the operation phase of the building.
- We remind you that an article has been published about a free EIA environmental impact assessment course by the UPV.
- And an article that deals with how an EIA environmental impact assessment is prepared with very useful diagrams and documentation.
The analysis can also be carried out from a multi-criteria perspective, placing in a single graph those impacts that are considered most important.
This type of analysis allows to identify which groups of materials or operations contribute something relevant from an environmental impact point of view either because they are the maximum contributors to a given impact or they present high contribution values to
various impacts.
It is appreciated as the "INSULATING family”Very frequently accused of being a great contributor to environmental impacts, in reality, it is very little relevant from the point of view of the impacts caused. While it is a great benefactor thanks to the reduction of the energy consumed.
The contribution of a family of products can be shown by means of graphs that allow detecting about which parameters of a product family cause the greatest impacts.
It is appreciated that for the insulating family the impacts are all very small. The maximums less than 2% of the total ACV of the building so there is no point in trying to reduce the environmental impact of an entire building.
Similarly, we see that the energy consumption has high environmental impacts in various indicators above 30% such as; Use of primary energy, Air Pollution, Depletion of fossil fuel resources, Destruction of the ozone layer and higher than 10% for the Greenhouse Effect.
It makes perfect sense, from an environmental perspective, to try to reduce the energy consumption of the building, even if this means using a little more insulation
Conclusions.
- Today, it is feasible and relatively simple thanks to the availability of environmental data to BIM models and IT tools partners carry out a life cycle analysis of a building There are therefore no excuses for not doing it!
- The LCA of a building It is not only useful to determine the different impacts caused by the building and its use, but what is more important identify which phases / products are responsible for the impact. The identification of the "responsible" phases / materials is the necessary and essential preliminary phase to be able to optimize the building from a point of view
environmental. - It makes no technical sense to try to justify the environmental sustainability of a building based on the selection / elimination of certain materials, if it is not evidenced that their contribution to the building's life cycle is relevant.
- The Environmental evaluation is multi-criteria and a prioritization must necessarily be established on which impacts it is desired to optimize. Since the greenhouse effect is the most commonly known impact, it is not the only one, and solutions that cause a significant displacement of impacts from one indicator to another should be avoided.
- The Analysis of the complete Life Cycle of each building must be addressed on a case-by-case basis, so that it turns out to be really effective.
