Tool Name
The Building Information Modeling Sustainability Assessment (BIMSA)
Overview
The BIMSA automatically evaluates common BSA metrics. The BIMSA is designed to work with Revit since Revit is a leading BIM platform in the AEC industry, and a Dynamo graph performs the computations. It can be executed in Dynamo or from the Revit user interface via the Dynamo Player. It takes as input a model of a single building that specifies site location as well as materials and dimensions (in metric units) of all elements. No further manual inputs are needed for the BIMSA’s current implementation in order to streamline the user experience.
The BIMSA encompasses metrics that can be computed directly or by proxy within BIM models and for which manual computation is time-consuming. Current metrics include footprint area, embodied GWP, and natural light. Footprint area is measured in m2 and approximated by the area of structural foundations and floors on the first building level. Embodied GWP is measured in kg CO2-equivalent and approximated by the embodied GWP of principal elements, namely structural foundations, floors, walls, and roofs. The BIMSA extracts total volumes for different material types then multiplies by respective embodied GWPs and densities (sourced from the literature and stored in an external CSV file). Natural light is measured as a ratio and approximated by the total window and curtain panel area over the total floor area, which is an established method for quantifying natural light in residential spaces. These three metrics are common in BSAs and considered meaningful measures of sustainability. Additional metrics can easily be added to the BIMSA if coded into the Dynamo graph and could include heat island effect (approximated by average shading area in a Revit solar study), solar energy generation potential (estimated directly by selecting surfaces viable for solar panel installation), and indoor air quality (approximated by airflow rate). A preliminary nonfunctional implementation for evaluating solar energy generation potential is already encoded in the BIMSA.
Outputs compare model values to industry standards (regulations or average values for different building types). It is desirable to be below industry standard for some metrics (i.e. embodied GWP) and above for others (i.e. natural light). Running the BIMSA with the Dynamo Player generates outputs only in a text and numerical format, but executing in Dynamo supplies additional bar plots to visualize discrepancies between model values and industry standards. Improving the BIMSA could involve making these plots visible in Revit or automatically downloading plots for the user. The BIMSA currently compares against residential building standards but different building types can be accommodated by updating the hard-coded standards in the Dynamo graph. A future iteration of the BIMSA could allow users to specify their building type as input then automatically adapt the standards shown in the output.
No custom Dynamo Nodes are needed for the BIMSA. The only required Dynamo add-on package beyond those covered in CEE 220C is NodeModelCharts by alfarok (used for plotting).
Teaser Images
Video Demo