Technology Toolkit for Sustainable Design at Orcutt Winslow PartnershipAECbytes Feature (May 11, 2017)

Last month, I wrote about the highlights of GRAPHISOFT’s recent conference in Las Vegas focused on users of its ARCHICAD, BIMx, and BIMcloud solutions, including keynote presentations by industry leaders, updates from GRAPHISOFT on its solutions, and learning sessions from power users and experts. Of the latter, one of the sessions that I attended was particularly informative as well as so relevant to the increasingly critical topic of sustainable design that it merits an extended look. This was a session entitled “Creating Your Technology Toolkit for Sustainable Design” and was presented by a team from the firm, Orcutt |Winslow, comprising Ashley Mulhall, Chuck Kottka, Matt Johnson, and Amy Kim. It provided an extensive look at how their firm has compiled a toolkit of applications to address different aspects of sustainable building design and meet the growing requirements of certification programs like LEED v4 and The Living Building Challenge. This article explores what these applications are and how Orcutt | Winslow is deploying them to design more energy-efficient buildings.

About Orcutt | Winslow

Orcutt | Winslow, also known as Orcutt Winslow Partnership (OWP) was founded in 1971 with the intent of applying new and innovative design solutions to architecture and driven by two main philosophies that still underlie the work of the firm today: one, a building must give back more than it takes; and two, that behind every well-designed building is an architect who took the time to thoroughly understand the client’s needs. Given its mission statement, the firm’s strong focus on sustainable design is clearly in line with its objectives and has also resonated with its clients, propelling it to become one of the largest architecture firms in the Southwest and ranked in the top 100 firms in the U.S. Its portfolio of work has resulted in over $6 billion in construction, with clients ranging from national healthcare providers to local universities, school districts and governmental agencies. Some examples of its recent projects are shown in Figure 1.

Figure 1. Some of OWP's recent projects: John C. Lincoln Deer Valley Hospital (top left); Sedona Performing Arts Center (top right); Grand Canyon University College of Arts and Sciences (lower left); and Gila River Health Care Administration (lower right).

From a technology perspective, two main aspects of the firm are noteworthy: it has always been a Mac-only firm and is a long-time user of ArchiCAD. It also seems to have imbibed ArchiCAD’s philosophy of openness and interoperability and has a wide variety of tools in its arsenal, not only for sustainable design but for other aspects of design as well. In this article, however, we will only be looking at its toolkit for sustainable design that it presented at length at GRAPHISOFT’s recent North American BIM conference.

Sustainability Standards

Before moving on to the tools that OWP uses for sustainable design, let’s look at the different standards the firm refers to, not just to get “certified” for meeting the criteria defined in them, but primarily to be guided in adopting and implementing different strategies for improving the performance of a design. These include the three standards shown in the graphic in Figure 2, which also highlights how they intersect and what their common focus areas are.

Figure 2. The three main standards OWP refers to for sustainable design guidance.

The WELL Building Standard, as the name suggests, is focused exclusively on occupant health and on how it is impacted by the built environment. Officially launched in 2014, this standard is managed and administered by the International WELL Building Institute (IWBI), a public benefit corporation. It provides a performance-based system for measuring, certifying, and monitoring features of the built environment that impact human health and wellbeing through seven health and wellness categories: air, water, nourishment, light, fitness, comfort, and mind (Figure 3). The standard is grounded in a body of medical research that explores the connection between the buildings where we spend more than 90 percent of our time and the health and wellness of their occupants. While this is something no architect will dispute, it turns out that it is possible to actually create spaces and enclosures that can be “certified” as improving the nutrition, fitness, mood, and sleep patterns of occupants. The WELL Building Standard is third-party certified by the same organization which administers LEED and is actually quite similar to LEED in that each of its seven categories includes prerequisites (or “preconditions”) and credits (“optimizations”). Also, like LEED, WELL buildings can be certified to three levels: Silver, Gold, and Platinum.

Figure 3. The seven categories in the WELL Building Standard used for measuring, certifying, and monitoring the impact of a building on its occupants.

The LEED (Leadership in Energy and Environmental Design) standard is, of course, the most common standard for green buildings around the world, and OWP uses the latest version, LEED v4, of the standard, which was released in October 2012. The new version has several advantages over the earlier version and the ones most critical to OWP are shown in Figure 4, including the source of the raw materials used in building products and the degree to which they are renewable and recyclable, the products themselves and the extent to which to which they use local and recycled content, and a performance based approach to design, operations and maintenance that calls for measurable results at every stage of a building’s lifecycle.

Figure 4. The key features in the newest version of LEED that help to guide OWP’s green design strategies.

And finally, the Living Building Challenge (LBC) is a sustainable building certification program created in 2006 by the non-profit International Living Future Institute. It is a lot more rigorous than a green certification standard like LEED as the fundamental idea behind the standard is that any building should give more to the environment than it takes, that it shouldn’t be just “less bad” and instead be actually regenerative (Figure 5). This calls for the building to not only have zero waste but also be net positive in its water and energy use rather than just zero. It may sound like a tall order, but is a great guiding principle for the spaces we create and several example of LBC certified buildings are showcased on its website, indicating that this is doable. The fact that OWP sets store by this standard highlights the extent of its commitment to creating architecture that is not only sustainable and healthy for its occupants but good for the environment as well.

Figure 5. The fundamental idea behind the Living Building Challenge.

The Toolkit

The design of sustainable buildings today requires not just an education in architecture but also an understanding of multiple aspects of building science such as product chemistry, computational fluid dynamics, embodied carbon, and life cycle analysis. This required OWP to assemble a toolkit that only includes ArchiCAD and familiar energy analysis tools, but also to reach into other disciplines and new technologies.

One of the first tools that the OWP team uses at the start of any new project is Climate Consultant, which provides extensive information about the local climate where the project is situated. This tool uses annual hourly EPW (EnergyPlus Weather) format climate data that is made available at no cost by the Department of Energy for thousands of weather stations around the world and translates this raw climate data into meaningful graphic displays that show the subtle attributes of climate and its impact on built form in that particular location. OWP finds the Psychrometric Chart, which is one of the more advanced features available in Climate Consultant, particularly helpful (Figure 6). It analyses the temperature and humidity of each of the 8760 hours per year in that location and plots them on a chart that also shows the most effective passive design strategies that can be used to potentially expand the comfort zone of occupants at any given time.

Figure 6. OWP’s use of Climate Consultant’s Psychrometric Chart for climate analysis.

For early stage climate analysis, OWP uses Sefaira, the cloud-based conceptual performance analysis tool that was launched in 2012 and which Trimble acquired last year. (For more on Sefaira, see the recent AECbytes article on Greenbuild 2016.) Since Sefaira does not (yet) have a plug-in to ArchiCAD which is the BIM application OWP uses, OWP uses Sefaira with SketchUp for conceptual design. The early stage feedback provided by Sefaira is critical to ensure the building has made a good start from a sustainability perspective (Figure 7). In particular, Sefaira’s Response Curve tool is very useful in providing a comparative what-if analysis of the impact of different design criteria such as shading, glazing ratios, orientation, U value, etc., on the design performance relative to cost.

Figure 7. The use of Sefaira by OWP for early stage energy and daylighting analysis.

Once the design has reached the design development stage, it is transitioned to BIM modeling in ArchiCAD, and at this stage, OWP uses two specific capabilities of ArchiCAD for performance analysis. The first is the Sun Studies tool, which allows an entire project or a selected part of it to be viewed in a real-life situation by choosing site location and defining the time period over which the lighting and shadow casting is to be studied. OWP uses this in conjunction with a tool called Velux which allows in-depth daylighting analysis within a space. Through the iterative use of both these tools, the design can be fine-tuned until the desired lighting conditions within the building are achieved (Figure 8).

Figure 8. Use of ArchiCAD (top image)and Velux (lower image) for sun studies and daylighting analysis.

Another ArchiCAD feature that OWP uses extensively is its Thermal Bridging analysis tool, which allows a 2D heat-flow simulation to be run on any element to identify those parts of the building that are responsible for heat loss and might cause vapor condensation as well as other unwanted effects. Again, OWP uses this in conjunction with Energy2D, another tool that provides not only thermal bridging analysis but can also run sophisticated CFD (computation fluid dynamics) simulations, allowing OWP to test out different materials and composites for building components (Figure 9).

Figure 9. Use of ArchiCAD (top image) and Energy2D (lower image) for thermal bridging and CFD analysis.

And finally, OWP’s toolkit also includes applications for cost estimating as well as carbon footprint and lifecycle analysis, looking at the sustainability impact of design designs in the long term. For cost estimating, it uses the popular application, RS Means, while for carbon footprint and lifecycle analysis, it uses the lesser known Athena EcoCalculator and Impact Estimator. With the Impact Estimator in particular—which is designed to evaluate whole buildings and assemblies based on internationally recognized life cycle assessment (LCA) methodology—it is able to assess and compare the environmental implications of industrial, institutional, commercial and residential designs, both for new buildings and major renovations. These are important to OWP in its participation in the Architecture 2030 Challenge, which requires all new buildings, developments, and major renovations to be carbon-neutral by 2030, and for which OWP is required to report the energy data for all its projects (Figure 10).

Figure 10. OWP’s report of energy data for one of its projects for the Architecture 2030 Challenge.

File Exports and Translation

With such a wide variety of tools in its sustainable design toolkit, the need to make them work together is critical to OWP. Not only do the different tools use different file formats, they also often have different ways of representing information which poses significant challenges in attempting to use them for the same project. For instance, the conceptual design energy analysis tool, Sefaira, uses only single-plane envelopes for its building models, which are not supported by ArchiCAD. A workaround to this problem is exporting the ArchiCAD model to SketchUp, cleaning it up there, and then feeding it to Sefaira. Alternately, OWP uses the Morph tool in ArchiCAD to create volumes for spaces, which can then be used by Sefaira for analysis.

Another tool that OWP uses is Solibri Model Checker (SMC) to ensure that the building has been modeled in ArchiCAD correctly. The ArchiCAD model is exported to IFC which is then checked by SMC to ensure that all the required elements are in the model and there are no geometry issues. While basic checks can be done with the free version of SMC, OWP uses the paid version of SMC to go further and run additional checks on the model, look at element conflicts, and verify that all the spaces are accounted for (Figure 11). SMC can even do a pre-check for energy analysis which is very useful to OWP.

Figure 11. OWP uses Solibri Model Checker to check the model and ensure it is ready for energy analysis.

Schedules and Templates

Given that sustainable design is highly data-driven, two additional functionalities—both of which are available in ArchiCAD—that are critical to OWP in its sustainable design toolkit are custom schedules that allow the creation of specific data sets that are needed for analysis, and the ability to create project templates that capture sustainable design workflows to apply to all projects.  An example of a custom schedule created by OWP showing the Embodied Carbon and Embodied Energy of materials used in a project along with common properties such as area, mass, and volume is illustrated in Figure 12. The quantity of materials comes directly from the building component data in the BIM model, and any changes to the model will be automatically reflected in the schedule. Another type of custom schedule that OWP creates shows the lifecycle assessment of all the materials used in the project, including information from Athena about where a material originates, distance of travel, shipping weight, and so on, all of which will determine the environmental impact of the project. 

Figure 12. Custom schedule created by OWP to show the total energy use of a project.

For templates, they contain most of the content that OWP uses for sustainable design in terms of the building materials and component types such as walls, slabs, doors, windows, and so on. Using a template ensures that any new project is already “pre-loaded” with the object types and materials that are used by OWP across all its projects, giving it a jump-start from a sustainability perspective. The templates themselves have been created so that they have as much real-world information as possible; for example, the Building Material Catalog would include information such as thermal conductivity (U-Value/foot), density and heat capacity, and embodied energy and carbon dioxide that are critical to energy analysis (Figure 13). Much of this information comes from industry standards such as ASHRAE. In addition to these objects being used for creating a project, the templates also ensure that this critical energy-related data is included when a project is exported for analysis.

Figure 13. The Building Material catalog that is part of OWP’s templates includes real-world energy-related data about a material.


The breadth and depth of the toolkit OWP has assembled for sustainable design allows it to meet rigorous certification standards like LEED v4, WELL Building Standard and the Living Building Challenge that are continuing to raise the bar for sustainable, high performance design. It is evident that OWP’s preferred BIM solution, ArchiCAD, does not provide a “one stop shop” solution for sustainable design; however, it does provide a sturdy backbone on top of which OWP is deploying a wide variety of supplemental tools to meet its high standards for sustainable design.

The firm has been somewhat limited by its choice of tools as it is a Mac-only firm, but given the resurgence of Macs and the growing move towards developing web-based applications that are platform-agnostic, this does not seem to be a serious limitation going forward and is likely to eventually fade away altogether.

For now, OWP has shown that, at least as far as sustainable design is concerned, we have the tools. All that is needed is the mindset.

About the Author

Lachmi Khemlani is founder and editor of AECbytes. She has a Ph.D. in Architecture from UC Berkeley, specializing in intelligent building modeling, and consults and writes on AEC technology. She can be reached at

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