FIGURE 20Once we have completely defined the materials in our present scope of assessment, we can get results by clicking on the ‘Save Report’ button. This brings up a window that allows us to select what information should be included in the report.

Getting ResultsOverview of Tally reports.

TallyTM Tutorial: Getting Results©2014 KT Innovations

FIGURE 21Tally offers a number of pre-formatted cradle-to-grave contribution assessments, organized by Life-cycle stage, CSI Division, and Revit Category. It can also provide an itemized bill of materials in case we wish to generate our own custom reports directly from Excel. After we enter some basic project information, choose a filename, and click save, Tally generates a pdf containing all of the contribution assessments that we selected. Since we were in a 3D view, Tally also places a screenshot of that view on the report’s cover page.

FIGURE 23Looking at a whole-building contribution assessment, sorted by CSI Division, we see that concrete makes up about 59% of the building’s total mass, but only 23% of its carbon footprint and 11% of its total embodied energy. Division 8, Openings and Glazing, however makes up roughly 4% of the building’s total mass, but contributes 14% of the carbon footprint and 15% of the embodied energy due to the intensity of manufacturing and processing of glass, aluminum and steel. Additionally, we notice that materials in Division 7, Thermal and Moisture Protection, have environmental impact contributions that are quite large in proportion to their mass. If we wanted to determine exactly which materials within Division 7 are the most significant offenders, we could turn to the contribution assessment by material, which reveals that stainless steel flashing bears the majority of these impacts, followed by a significant contribution from the EPS insulation board used throughout the project.

FIGURE 22Tally makes use of contribution assessments to show the relationship between building elements or materials and their corresponding environmental impacts across a range of impact categories such as Global Warming Potential, Acidification and Ozone Depletion. Each contribution assessment is displayed as a series of stacked bar graphs showing mass and impact category breakdowns. Totals are printed at the top of each stacked bar, and the colors in each bar correspond to those seen in the legend below. For a focused view of global warming potential and embodied energy, pie charts are provided on the facing page.

FIGURE 24 AND 25If, we wished to study impacts based on where materials occur in the building, we could turn to the contribution assessment by Revit category, which can also be itemized by family type or by material. This view is especially useful during the design process as it lets designers focus in on particular assemblies and components in the model and make comparisons between elements that serve similar functions, such as a series of wall types or flooring assemblies, for example.

FIGURE 26At the back of the report is an appendix that includes a description of Tally’s calculation methodology and a glossary of LCA terminology. This is followed by details of all of the materials used in our assessment. Each of these items contains data about a given material’s life cycle inventory, entry scope and source, along with a list of all Revit families where it was applied in the model.

Tally also generates a bill of materials saved as an Excel file, with Pivot tables corresponding to the same classifications that are found in the pdf report, allowing users to customize their own reporting formats and focus in on specific design questions.

FIGURE 27In addition to calculating the environmental impact of a whole building, Tally also facilitates comparison between design options. A design option report resembles a full building report in most aspects. One key difference is that contribution assessments are now shown with a separate stacked bar for each design option, scaled according to the largest total within each impact category. In this manner, one can simultaneously evaluate the share of impacts within each design option and compare the cumulative impacts across two or more design options in a Revit model.

FIGURE 28In this comparison of two lower level exterior envelope options, we see little difference in environmental impacts, despite different construction types. While a second comparison of multiple upper level envelope options reveals our Opaque Panel Option as having the lowest impacts across most categories, in part because that design option requires lower quantities of EPS foam insulation and structural steel.