Life Cycle Assessment#

This task can be used to estimate the environmental costs of a structure by doing a life cycle assessment. Results can be used in early planning steps by comparing different variants of a system with each other.

Global Warming Potential#

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The material table lists every material in the project. For each material, the Global Warming Potential can be defined for the following Life Cycle Phases (Phases according to DIN EN 15643):

  • A1-A3 Product Stage

  • C3 Waste Processing

  • D Recycling Potential (per default deactivated, can be selected for the assessment)

The Phases which are displayed in the task have been selected based on the recomendations from the German Sustainable Building Council (DGNB) and on availability in the datasets.

If a table field is left empty, no GWP value will be stored in the database.

Select EPD from ÖKOBAUDAT#

When the task opens for the first time, a data set for the assessment can be selected. Both versions of ÖKOBAUDAT, according to EN 15804+A2 and according to EN 15804+A1, can be selected for the default values.

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If selected, the mostly used standard materials are per default matched with corresponding datasets from the german database ÖKOBAUDAT (published by the German Federal Ministry for Housing, Urban Development and Building (BMWSB)). For the default data sets, avarage datasets are preferred over general data sets. An exeption is building steel, for which the GWP values more depend on the member form than on the steel grade and for which therefore corresponding data sets cannot be selected in advance without knowing the details of the structure.

Materials can be manually matched with data sets from the ÖKOBAUDAT database. To do so, select a material from the list and click on “select EPD from ÖKOBAUDAT”. The data set selection dialog appears. Shown are the currently available datasets from the ÖKOBAUDAT.

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The data sets are read from a CSV file included with the installation. This CSV file was downloaded from the ÖKOBAUDAT website at the time of release. Possible updates in the ÖKOBAUDAT will then be available with the next SOFiSTiK Service Pack. The data set list can be filtered with the filter options filter_small or searched for specific Names or Classifications.

Attention

Independent from the selection for the defaults at the first start of the task, EPDs from EN 15804+A1 and +A2 can be selected. Nevertheless, it is NOT recomended to mix EPDs from both data sets in one project.

Units#

The basic unit for the global warming potential is kgCO2e = kilogramm CO2 equivalent. The values for the individual materials can be defined per mass or per volume.

The default units for the CO2 Equivalent, the CO2 Equivalent per mass and the CO2 Equivalent per volume are defined in the material section Unit set in the System Information dialog. Per default, the task uses for all metal materials (steel, aluminium,…) the CO2 Equivalent per mass. For all minerial materials (concrete, timber,…) the default is the CO2 Equivalent per volume.

If a dataset from the ÖKOBAUDAT is used, the unit from the dataset is set in the task.

All units can be changed by clicking on the unit and using the dropdown menu.

Calculation Options#

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Select element types#

This selects which kind of elements should be considered in the assessment. The following elements can be selected:

  • Beam-, Truss-, Cable-elements

  • Plane elements

  • Three-dimensional solid elements

  • Design elements

Hint

Design elements usually are used to integrate results from different structural elements for the design. Therefore, the selection/deselection of design elements does not change the total sum of masses/volume, nor the total Global Warming Potential. The Assessment of the design elements results can be used for an evaluation of the different design element member types (e.g. Columns, Shear Walls, Building Core,…).

Evaluation of#

This defines by what criteria the Global Warming Potential should be evaluated. There are three options, from which one has to be selected for a proper assessment. Therefore, if no option is selected, an evaluation by primary groups will be carried out. The assessment can contain an evaluation of:

  • Materials

  • Groups

  • Secondary Groups

Options for concrete structures#

With the options for concrete structures the consideration of reinforcement and tendons can be controlled. If no option is selected, the cross sections/areas are calculated as if they would only consist out of concrete.

If Consider reinforcement is selected, the reinforcement materials and their GWP is considered in the assessment. For the calculation of the volume/mass, the assessment considers:

  • the predefined reinforcement of the cross section/the area, when no design case is available

  • or the reinforcement from the last created design case.

If Consider tendons is selected, the tendon materials and their GWP are considered in the assessment. For the calculation of the volume/mass, the assessment considers the tendon volume/mass.

In both cases, the concrete volume/mass is reduced consistently.

Output#

If Print results is deselected, no output tables are printed in the report. This can make sense if tables for the life cycle assessment are custom designed with the Result Viewer

Excel Export#

The Excel Export functionality can be used to store results from different variants of a project in one Excel file for comparison.

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Select a .xslx file for the export.

Define a number and a title for your variant. When changes have been made in the model and the system has been calculated again, increase the number of the variant and change the variant title before processing the task Life Cycle Assessment again. Then the GWP results of the “old” model will not be overwritten, and of both assessments will be stored in the Excel file.

The Excel file will start with an overview sheet comparing the total GWP per phase and variant. Additional sheets for each variant will show detailed results for material, group, secondary group and design element type (depending on the selection in Evaluation of).

Tip

Use the Excel Export to save your assessment before making changes in your model, since GWP results will not be longer stored in the SOFiSTiK database when a model is recalculated.

Further Information#

ÖKOBAUDAT: https://www.oekobaudat.de/no_cache/en/database/search.html

Booklet from the Attitude Building Collective with practice-oriented information on Life Cycle Assessment in construction: https://attitudebuildingcollective.org/en/building/lcabooklet/