The value of building information modeling (BIM) is understood by the design-build industry and increasingly recognized as a valuable tool in ongoing building design, construction, building operations and maintenance. But does landscape architecture, which traditionally starts with hand-drawn sketches and 2D computer visualizations, and more recently 3D schematic models, fit in the bigger BIM picture? Absolutely. Not only is there a growing requirement for complete project deliverables produced in a BIM application — especially for local, state and federal government agencies — but the emphasis on sustainable sites and green buildings is also driving the adoption of BIM among landscape architects.

Benefits and Challenges of BIM

Landscape architects are incorporating BIM processes into their workflows for many of the same reasons architects and structural engineers do: early identification of problems and conflicts, easy comparison and evaluation of options, clear documentation of the details of the project, and more effective communication between team members. However, almost all BIM software is purpose-built for rectilinear building design rather than nonlinear and more complex elements, such as plants, water, multi-sloping hardscapes and topography, which makes using BIM for landscape design challenging with some of the software tools available today.

“Despite the steep learning curve, incorporating BIM into landscape architecture adds so much value to the entire lifecycle of a project,” says Lauren Schmidt, designer at Gustafson Guthrie Nichol (GGN) in Seattle. “The real power behind BIM is in the data associated with the 3D model, similar to how GIS has information associated with 2D geometry. As we design we can specify that a wall has a certain thickness and is made of a certain material, and as changes are made to the data or geometry of the wall, those changes will update throughout any schedules and views associated with that wall.”

Schmidt’s employer, GGN, is conducting its first BIM project using Revit to coordinate and document the landscape of the Washington State convention center Addition project in downtown Seattle, which encompasses four city blocks and includes commercial, residential and retail programs, along with the Convention Center facility. “Building a virtual model of a project prior to construction allows you to address design and constructability issues earlier in the process, thus reducing the occurrence of costly change orders in the field and, in the end, delivering a better product,” Schmidt says.

“Most of the architects we work with use Revit, so creating a landscape model in Revit is extremely useful for visualizing our design relative to the architecture while helping us stay coordinated throughout the entire process. When we work in other programs, such as AutoCAD, Rhino or SketchUp, the opportunities for coordination are unfortunately limited. Also, changes made in one application are not automatically shared with another application; there is usually an export process, which can frequently be a limiting factor. But regardless of the software used, there must be a procedure in place for sharing at regular intervals so that everyone stays on the same page.”

Modeling landscapes in Revit or any BIM software is not without challenges. “The biggest limitation of using Revit for landscape is the lack of landscape-oriented workflow, but there are helpful plug-ins, such as Topo Align, which automatically attaches topography to hardscape faces and edges, and, of course, Dynamo, which allows the average user to essentially create their own add-ins,” Schmidt says.

“Developing an in-house content library specific to your firm’s needs is one of the initial hurdles to get past with any BIM software, due to a scarcity of content included in most design software products. But content can be built up over time and continuously reused in an incremental and manageable transition.”

Landscape-Specific BIM Software

In the past, software tools that produced only 2D designs did not provide the functionality required for landscape architects to work in 3D and deliver BIM-compliant deliverables, and plug-ins to a general CAD software were difficult to work with. This situation motivated Vectorworks Inc. to develop standalone BIM software with rich information modeling specifically aimed at landscape architecture.

Vectorworks Inc., a wholly owned subsidiary of The Nemetschek Group, introduced the Vectorworks Design Series of products in 2001, including Vectorworks Landmark with dedicated BIM tools for landscape architects. The intelligent site-specific objects provided BIM workflows for site design years before landscape architects considered BIM a process. Users at that time just enjoyed the idea of designing in 2D and 3D at the same time, with intuitive objects that were built for their site-specific design needs.

“Vectorworks was founded in 1985 and the original software was not industry specific, although landscapers were using the tools,” says Eric Gilbey, product marketing manager at Vectorworks. “Landscape design professionals weren’t referring to it as BIM, but the functionality was there. With the release of the Vectorworks Design Series in three products, the software integrated 2D and 3D representations and has continued to evolve with smart hybrid objects and harvested data in worksheets, formatted to fulfill BIM workflows.”

Vectorworks emphasizes industry involvement to help identify the current and future needs of landscape architects. The company performs research into technology innovations and tracks user requests to ensure Vectorworks Landmark will continue to support the needs of current and future site designers and land planners.

“Over 70 percent of the updates and features in the 2016 and 2017 version of Vectorworks were born from customer feedback,” Gilbey says. “Our mission is facilitating landscape design. The landscape architect shouldn’t have to spend a lot of time creating content, like a plant or tree.”

Landscape architects, trying to influence the technology change, are being more proactive about adopting BIM, according to Rubina Siddiqui, product marketing manager at Vectorworks. “However, in general, the tools have not kept up with demand, possibly due to the smaller size of the site design market. In response, Vectorworks has developed an intelligent modeling platform that automates the landscape design process and yields a better end product.”

Green Buildings

Energy efficiency and sustainability are important drivers for using BIM in site design. In most cases, professionals seeking to implement energy efficiency and better performance in their landscape design projects are doing so with the guidance of rating systems like LEED and SITES and the WELL Building Standard. These systems require quantifiable documentation of the expected efficiencies gained.

LEED-certified buildings are designed to use less water and energy and reduce greenhouse gas emissions as compared to conventional buildings. SITES guidelines focus on the surrounding ecosystem health, for example by reducing storm water runoff, providing wildlife habitat and improving air quality. The WELL Building Standard includes seven categories, including air, water and light, which contribute to the health and wellbeing of people in the building. The amount of data needed to verify any of these certifications is overwhelming to calculate by hand.

“Vectorworks Landmark is well suited for tracking compliance with rating guidelines,” Gilbey says. “The intelligent objects directly report this data to built-in worksheets where calculations are made to complete the energy efficiency documentation process. In many cases, the objects perform multiple analysis tasks. For example, when conducting solar studies, a landscape architect may position trees to minimize solar gain and at the same time, use the trees to compute the amount of carbon to be sequestered over the number of years those trees will benefit that project. You can also analyze water efficiency in irrigation and make sure to use the right equipment and the right type of plants. The user can add other relevant information on these smart objects themselves, like solar reflectance on pavements and performance standards for site furniture.”

As communities continue to address climate change and degradation of the natural environment, resource management will become even more important. Design software like Vectorworks Landmark that takes into consideration requirements for water, vegetation and soil management will facilitate monitoring and documenting the impact of buildings and other human activity.

Compatibility

Landscape architects may choose to use general purpose CAD/BIM software and plug-ins to alleviate compatibility issues. As the industry standard for architects and structural engineers, CAD is a trusted and familiar solution. However, the CAD software is not landscape-specific and not automated for landscape applications. As a standalone landscape product, Vectorworks Landmark is more functional and is compatible with BIM building designs.

“If our users need to exchange geometry and data of the proposed site design, we recommend exchanging with the Industry Foundation Class (IFC) format,” Gilbey says. “In many cases, however, our users are still finding success in exchanging with DWG, PDF and various 3D file formats to provide a collaborative model of the proposed site with the proposed building.”

Whether the process of combining a building design and site design into one model is seamless or not depends on the handling of the particular BIM software being used. In certain applications, some exchanged elements may easily be recognized as a similar BIM entity (i.e. wall, slab, steps) while other applications may only recognize these objects generally (i.e. BIM proxy objects). A BIM proxy object, which still has the geometry and data attached, might or might not be further manipulated as it could have been in its native program. It depends on how well that BIM application plays nice with the other objects. Some firms may not want others to have the ability to change their BIM models, which makes this constraint acceptable as long as a separate landscape design that meets BIM requirements is produced.

“Collaboration with BIM models within programs like Solibri or Navisworks is about seeing the models together to ensure they are in sync with each other,” Gilbey says. “At that point, any existing conflicts or clashes are identified and resolved before moving into construction documentation.”

Landscape BIM is Here to Stay

The bottom-line cost and time savings experienced by users of BIM in landscape design will drive the continued development and expanded functionality of landscape-specific software.

“Just as we have seen with the architectural design industry, we expect landscape architecture to continue to use BIM processes,” Gilbey says. “The goal will be to save clients in their site installation costs, preserve precious resources through better water, soil and vegetation management, and work more efficiently with easier and faster workflows from schematic design to construction documentation.”

“Landscape architecture is such a broad profession with a wide range of project types, we just have to be flexible and open to different processes for different projects, depending on the requirements,” Schmidt concludes. “We must continue to engage with BIM and other design computation tools to ensure the software evolves to meet our needs, hopefully sooner rather than later, because the benefits far outweigh the inconveniences.”