How can we assess the environmental impact of building materials early in the design process, when life cycle-based choices can still be made?
Building materials consume significant natural resources and energy in their manufacture and deployment. Though architects today are invested in reducing the energy used to operate buildings, few have the resources and expertise to deeply analyze the environmental impacts of their material choices. As energy efficiency becomes more and more crucial to the work of architecture—and energy codes become increasingly stringent—embodied energy, carbon counts, and other environmental impacts of building materials will become a proactively calculated and well understood factor in reducing the total amount of resources buildings consume.
Quantifying environmental impact typically involves performing a Life Cycle Assessment, which is a relatively new and confounding practice for most architects. Currently, no efficient means exists to evaluate environmental impact of materials during the design and planning process, when it can have the most influence on design decisions and building performance. An architect needs this impact data at the time of material specification, but the laborious process required for calculating embodied environmental impact across a broad range of design decisions prevents this from happening at crucial moments in the design process.
In principle, Building Information Modeling (BIM) ought to enable architects to acquire this information, but in practice, projects are not modeled to a sufficient level of detail to account for all of the materials in a building at their actual volume. In order to address these challenges, we invented Tally™, a Revit app that allows users to imbue each assembly with information about the architectural products it contains. Tally™ quantifies embodied energy along with other environmental impacts and emissions to land, air, and water. It can be used for whole-building analysis or for comparative analyses of various design options, and it can account for the diverse range of material classes defined in a BIM model, as well as materials that are not modeled explicitly.
Using BIM software involves a process of optioning before the building design is fixed, with the designer defining assemblies, formulating questions about materials, and evaluating a variety of alternatives. By plugging into this iterative process, Tally™ allows architects to move from typologies and “rule of thumb” calculations of environmental impact to real-time assessments at pivotal moments. The tool facilitates the process of translating Revit materials into discreet building materials and quantities; it then generates a Bill of Materials for the full building or constituent parts, automatically updating quantities as the design changes. No other currently available environmental assessment tools can achieve this kind of inventory at the same resolution.
Once the Bill of Materials has been generated, Tally™ draws environmental impact information associated with the manufacturing of those materials from the associated databases. It presents this data to the user—sorting, grouping, and displaying information to answer design and material-selection questions at hand. Unlike other environmental assessment tools, which tend to export data to unwieldy spreadsheets, Tally™ allows users to produce data graphics that are readily comprehensible, transparent, and customizable. In this way, information that is normally abstract becomes very well defined, which allows for much more accurate and nuanced decision-making.
Tally™ is developed in partnership with Autodesk Sustainability Solutions, a division of Autodesk, and PE INTERNATIONAL, a global leader in life cycle information and sustainability consulting. It is geared for use primarily by architects and design teams; however, a wide base of other potential users includes life cycle assessment and sustainability consultants, builders, engineers, and industry partners. Further information is available at http://ktrg.kierantimberlake.com/tally/.