Virtual reality as a tool for sustainable design

by sadia_badhon | June 4, 2020 10:59 am

by Amber Bartosh, RA, LEED AP, and Christina Aßmann, NCARB, LEED AP, CPHC

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Recent developments in virtual reality (VR) technology allow for the visualization of unbuilt information as full-scale occupiable environments, providing previously unavailable insight to designers, clients, and other stakeholders. The capabilities of these Technologies offer opportunities for communicating and analyzing the quantitative and material aspects of the design decisions related to sustainability and the built environment in an immersive and understandable way, both for the discipline and the larger public. At Nuthatch Hollow in Binghamton University (New York), the building team is utilizing VR as a visualization and simulation tool to support the project’s sustainability and educational outreach goals.

Nuthatch Hollow is an environmental classroom and research facility located on a 28-ha (70-acre) nature preserve close to the campus. The 279-m² (3000-sf) facility will be used primarily by the varsity’s environmental studies program for teaching and research, as well as by the larger university for gatherings and community-based educational sessions. The project team is pursuing both Living Building Challenge[2] (LBC) and Passive House Institute U.S.[3] (PHIUS) + 2018, Getting to Zero, certifications as a way to improve the overall resilience[4] of the building, reduce the size and upfront cost of the onsite renewable energy system, and push the market for sustainable products and construction methods. VR has proved an invaluable tool for conveying the environmental analysis inherent in decision-making, as well as incorporating interactive educational content to facilitate understanding of the sustainable quality of the built environment.

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Methods

In addition to using VR as a design tool to represent the full-scale spatial and aesthetic qualities of the Nuthatch Hollow project, the design team aimed to extend the technology’s capabilities to represent additional characteristics critical to achieving PH targets, including daylighting, ventilation, and public education outreach. The creation of this multi-faceted representation of the project required the design team to implement a variety of tools and methods, which engaged building information modeling (BIM), simulation, analysis, and user interaction platforms intended for video game production.

BIM to VR for spatial visualization

The design team used dedicated software to translate the BIM model into a VR-friendly environment. This method created a fluid relationship between the working design model and VR, which supported the building team’s use of the virtual environment in the design evaluation and project management process. This model was employed primarily by the in-house design team to communicate aesthetic decisions to themselves and the client, as well as to analyze shadow patterns and identify potential glare locations.

The direct connection between VR and the BIM model enabled the modification of design elements in real-time. Shifting elements in the BIM model were experienced in VR instantaneously. A fast-forward simulation of a year’s cycle of sun exposure and resulting shade patterns helped identify potential glare issues during specific time periods. Focusing on those critical time periods, changes were made to the model on the spot with immediate visualization of the results. Using this method, interior acoustical baffles were carefully placed to mitigate glare on the teaching surface. In this way, VR helped implement the holistic thinking LBC relies on—everything is connected in a purposeful way and elements can serve multiple functions.

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VR for daylighting analysis representation

To minimize the need for artificial lighting and the impact it has on the energy balance, while weighing out inherent heat loss incurred through window openings, it was imperative to calibrate the daylighting strategy to accommodate a sensible glazing-to-wall ratio. Modeling tools to get 2D daylighting representations were utilized to shape the initial design. Bringing those design assumptions into VR adds the value of 3D understanding and decision-making. Using visual cues, invisible energy components (e.g. daylighting) affecting the perceived quality of the indoor environment were manifested in a 3D quantitative representation. Both the quantity and quality of daylighting was experienced and double-checked in VR using a visualization method developed by the Interactive Design and Visualization Lab (IDVL) at Syracuse University, New York (read “Virtual Environment for Design and Analysis [VEDA]: Interactive and Immersive Energy Data Visualizations for Architectural” by Amber Bartosh and Krietemeyer Bess). This method creates a 3D grid of cones within the virtual space. The cones are color-mapped to match the intensity of the daylighting at that point. The orientation of the cones indicated the primary direction of the light trajectory. Users in the VR walkthrough could turn on and off the daylight analysis visualization using a customized menu.

To create the 3D daylighting analysis a simplified version of the BIM model was created. This model was used to create multilayer analysis of daylighting availability at different times of the year using a daylighting and energy modeling plugin. The resulting false-color daylighting values were mapped on the 3D grid of spheres, which were modeled separately and imported into a video gaming engine. By importing the model into a video gaming platform, the design team had the ability to introduce customized content that was not part of the BIM model. This included both the daylight spheres themselves and the menu giving users control over their presence while in the walkthrough.

VR for ventilation representation

Nuthatch Hollow is a wooded site that did not require additional architectural shading to meet sustainable cooling targets. Conversely, it was determined heating targets would be the most challenging to meet if the project relied on unobstructed winter heat gain. Further, natural airflow has an interesting existence at the intersection of LBC and PH. LBC requires operable windows as part of the Health and Happiness Petal whereas PH relies solely on efficient, continuous mechanical ventilation (consult the Living Building Challenge 3.0 Health & Happiness Petal Handbook). Natural ventilation can support energy savings, especially in regions like central New York where humidity is not prevalent during shoulder seasons. To prevent energy waste, reed switches at the window contacts turn off the operation of the mechanical systems when the windows are open. These devices can be configured to temporarily disable heating or cooling when a window has remained open for a certain amount of time and then re-enabled when the window has closed. The specific operational mode and delay patterns can be tailored to project needs. This solution allows the user to open and close windows when outdoor conditions are favorable without wasting power.

Additionally, for the Nuthatch Hollow project, foam-flush composting toilets were specified with a composter beneath. This requires continuous ventilation. Exposure to constant airflow is necessary to allow the mixture of toilet waste and bulking material to convert to usable compost and liquid fertilizer. The continuously operating composter fan creates negative air pressure at the toilet fixtures for odor control. The challenge was to accommodate this continuous exhaust within a balanced ventilation system and still meet PH’s stringent heating limitations. The project team determined the risk of dispersing toilet room odors throughout the entire building was too great if the composter exhaust air was run through the main energy recovery ventilation (ERV) unit. One solution was to dedicate a separate heat recovery ventilation (HRV) unit to the composting toilets, which will supply into the washrooms and exhaust directly from the composter unit, thereby containing most, if not all, odors within the washroom ventilation loop. Pathfinder, the mechanical, electrical, and plumbing (MEP) consultant, and the composter manufacturer still voiced concerns with this approach, which led the building team to look at tweaking the continuous airflow to the absolute minimum while still meeting the rigorous Passive House requirements.

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To visualize the ventilation within the project as a 3D entity, this complex system of airflow utilizing windows, fans, and mechanical means had to be modeled. This proved to be a challenge, and the design team initially chose to focus on natural ventilation visualization with other aspects of the ventilation system identified separately. To do this, the simplified model was run through a computational fluid dynamics (CFD) analysis tool, and ventilation data was exported as a CSV file containing x, y, and z positions and RGB values related to relative velocity of airflow. The CSV file was imported by using a particle generating app in the video gaming engine, which created a color particle at each corresponding point in the model. Particles near areas of ventilation intake, like windows and doors, were red while the ones near the center of the room were blue. The direct import of the CSV file cut down on modeling time, but reduced the amount of control the design team had on the final visualization. Ultimately, the design team assessed the static colored particles were ineffective in communicating ventilation. Therefore, they opted to synthesize the analysis results into a monochrome but animated approximation of airflow paths during passive and mechanical ventilation conditions. The team is continuing to develop and test alternate means for visualizing quantity and direction of airflow systems within the VR environment.

VR for sustainable education outreach

PH and LBC focuses on human comfort as a measure of how an environment operates from a thermal, acoustical, visual, and air quality standpoint. While high-performance buildings are designed to optimize the built environment, appropriate human interaction with it is essential. Additionally, IDVL integrated educational blurbs within the virtual environment to highlight key sustainability features of the building. For example, when one virtually strolls through the building and enters the restroom or the viewing platform in the mechanical room, educational signage pops up teaching about LBC’s Water Petal and how PH requirements are addressed. Another educational note highlights the composting toilet, a commonly used strategy to help achieve LBC’s net-positive water requirement for a closed water loop and all waste processed onsite. Other notes highlight the ceiling fans and acoustic baffles mentioned before to help users understand the multiple layers of design consideration that are imperative in creating good space and meeting PH criteria.

Results

Ultimately, the design team created and tested two separate, virtual Nuthatch Hollow environments: a BIM/VR model and a simulation data model in a video gaming platform. These models were exhibited and tested during in-house project management meetings, client presentations, and a green building conference. User feedback for both models was collected informally through discussion while in or after visiting the Nuthatch Hollow virtual environments.

Users immediately recognized the value of VR in both models to represent the project at full-scale prior to construction. Designers and clients most appreciated the responsiveness of the quick change and test aspect of the BIM/VR model. This was most effective in analysis of the shading and potential glare conditions throughout the day. Team members were already familiar with both the environmental design considerations and moving through the VR environment. The fluidity provided by the VR software eased the learning curve of using the technology as a design tool, but limited the possibility for experiencing non-visual information like ventilation patterns.

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Public use resulted in a number of questions, which reflected intensive engagement with the project and its represented content. This type of engagement is difficult to achieve using previous representation methods, including animation, because the user is simply not as ‘in’ the project if one is looking at a screen. Non-headset wearing participants were able to see the users experience on a 2D screen—while this helped to demonstrate the project it was significantly less immersive than when using the head-mounted display.

The simplified model imported into video gaming platform was not as dynamically responsive as the BIM/VR model, but it addressed user interaction and performance data by implementing external tools. The model and its analysis were predetermined in alternate programs and imported separately. However, the video gaming model gave the designer the most control over the user experience. In response to user feedback, fixed ‘teleportation’ points situated within the model helped direct circulation and kept users from teleporting into walls or unoccupiable parts of the model, an issue with new VR users initially. Additionally, the video gaming model’s integration of content related to the comfort and non-visual performance of the Nuthatch Hollow project prompted a user-designer discussion that was less about the technical aspects of visualization and more about the consideration of elements like daylighting and ventilation in the design process. Thus, the value of these visualizations as represented currently is more awareness generating than evaluative.

Conclusion

The resulting work demonstrates the value of using VR to provide insight to designers, clients, and other stakeholders, particularly when there are complex conditions and might not be easily conveyed through conventional representation methods. The work also exposes a gap between current architecture, engineering, and construction (AEC)-focused VR software—where the goal is spatial and visual representation—and VR-immersive environments with the potential to convey non-visual, quantitative, and energetic aspects of a project related to sustainability and the built environment. This gap is, in part, due to an existing disconnect between modeling and analysis tools used to evaluate a project. These tools may belong to other disciplines or consultant realms that are beyond the designer. In many cases, these programs require a more simplified model than BIM and the output is charts or spreadsheets. These non-graphic representations require translation and spatialization prior to importation into the VR environment. In other words, the 2D data has to become 3D before it can be integrated into VR, and there is no standard for this translation currently.

It is estimated in 2022, the augmented and virtual reality market[9] will reach $209 billion. As VR becomes a more ubiquitous tool in the AEC community, the design team expects the increased interest will prompt and support additional 3D VR visualization and/or other sensory representations that address a more holistic design method in a manner similar to the whole building approach of PH.

[10]Architect and interior designer Amber Bartosh, RA, LEED AP, is an assistant professor at Syracuse University School of Architecture, a Syracuse Center of Excellence Faculty Fellow, and co-director of the Interactive Design and Visualization Lab (IDVL). She received her BA in art and architecture from Rice University and her MArch from the Southern California Institute of Architecture. Bartosh’s work focuses on the sustainability and resilience of emergent materials and tools for architectural application through physical prototyping, advanced visualization technologies, and hybrid reality simulations. She can be reached at abartosh@syr.edu[11].

[12]A senior project architect with Ashley McGraw Architects, Christina Aßmann, NCARB, LEED AP, CPHC, has more than 15 years of professional experience working on a variety of project types. Aßmann’s work embraces the integration of design, sustainability, and exceeding her client’s expectations. She holds the German equivalent of a MS in architecture from the Universität Stuttgart, Germany, and a MArch from the University of Kansas. Aßmann can be reached at christina@ashleymcgraw.com[13].

Source URL: https://www.constructionspecifier.com/virtual-reality-as-a-tool-for-sustainable-design/

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