This is part of the Landscape Architecture + BIM in Practice series, which features landscape architects using BIM within professional practice.
HOK is a global design, architecture, engineering and planning firm with 24 offices across the US, UK, UAE, Canada, India and China. With about 1,800 people worldwide, HOK currently employs about 100 landscape architects, urban planners and urban designers.
I recently spoke with Brandon Hartz, a registered senior landscape architect based in the firm’s Washington, D.C., office. Out of about 100 people at HOK’s D.C. office, there are 10 people within the planning group, including six landscape architects. This team frequently collaborates with HOK’s New York and Atlanta offices and does work in the Middle East with the firm’s Dubai office.
Brandon has been involved with BIM at HOK for the past several years and he was able to share how the firm has used BIM within the realm of landscape architecture.
BIM at HOK
HOK initially implemented BIM in their landscape architectural work because of a desire to collaborate across the entire design platform. As a multidisciplinary design firm, collaborative thinking is an integral component to project development and delivery, and BIM provides a consistent language for that dialogue to occur. Although the ultimate goal is a 100% migration of projects to a BIM platform, about half of the current landscape projects are being completed in BIM and the other half are done in AutoCAD.
A typical BIM project at HOK will be implemented using Revit, though Brandon acknowledges that there are exceptions depending on project circumstances. In the early stages of a project, Sketchup may be used to express simple three-dimensional form. If a project has a particularly complex form, then Rhino might be used. When a team is still using AutoCAD, a number of plugins are available, including AutoTURN, ParkCAD and LandFX. While they do have AutoCAD Civil 3D in the office, it is not frequently used.
The Washington, D.C. office’s landscape team primarily uses BIM for design and documentation, and occasionally provides site models to the architecture department for visualization purposes. Overall, they have had many successes with documentation efficiencies. This has provided the ability to re-scale views and quickly generate elevations of complex elements like fences, guardrails and sloping/ stepping walls, which in the past would have been drafted independently.
Making the Transition
Their team initially received BIM training about five years ago, yet did not implement the process on a project right away. At the time, the team was in the middle of several large and complex projects that were too far along to start in BIM. Other projects were too small and their schedules too short to handle the learning curve of a first project.
Eventually they found the right project to pilot BIM: a building entrance modernization for a confidential healthcare client. According to Brandon, it was a good pilot project since it was limited in scale and straightforward. There was also plenty of time in the schedule, since the architectural team was doing a renovation that required more documentation time. The site was essentially a flat, urban drop-off entry to the hospital and was easily manageable within three dimensions.
“One of the biggest insights from that first project was understanding the workflow and how it differs from working in AutoCAD,” Brandon admits. “In fact, trying to understand and maximize workflows is somewhat of an ongoing process. It becomes easier, especially once you have content that can be reused, such as components and tags.”
Benefits and Challenges
One of the biggest benefits of BIM utilization Brandon has seen is the increased coordination with building engineers, particularly on above ground structures like roof decks and green roofs. “It has made it easier to coordinate the landscape with the building architecture, structural beams, and plumbing and electrical system connections. Being able work with architects and engineers who are already well-versed in BIM is an added benefit.”
Another substantial benefit is the ability to design and document at the same time. Teams can show 3D views to the client in order to get buy-in and approval. If changes are needed, the model can be adjusted while all of the documentation remains up-to-date, making for an extremely efficient workflow.
Within Revit, one of the biggest challenges is establishing a workflow for changing topography and grade. It is a challenging issue since even the workflows between Revit and Civil 3D are limited. Brandon says that he would be unsure how to accomplish some projects in BIM. He noted that on previous projects with substantial topography or grade, the civil engineer would sometimes change the grade up to three times a week. In a case such as this, maintaining a live 3D topographic model would be too time-consuming and costly.
Case Study: Washington, DC Roof Terrace
A recent project for a confidential client included a roof terrace that was successfully implemented using BIM. Brandon notes that being able to generate 3D views was very important for this project. “The roof terrace was long and narrow. We needed to show how the client could break up the spaces by creating landscape rooms to define semi-private and public areas, while also allowing for the free-flow of people.”
With those 3D views, the design team could show what a perspective view down the length of the roof would look like, including how overhead canopies would create shade. They were also able show how the landscape elements, such as the paving pattern and guardrail, were respectful of the building geometry.
From the technical side, the team used several different architectural tools within the landscape. Using Areas for planting areas enabled them to calculate plant quantity based on spacing. They also created an undulating green roof component with a Floor modified by sub-elements, which allowed them to generate an accurate grading plan using spot elevations. The glass guardrail was modeled as a curtain wall to create custom breaks in the glass to match the building architecture, unlike Railings which offer limited flexibility.
Advice for Other Professionals
Brandon has several pieces of advice for other landscape architects that are considering implementing BIM:
1. If you undergo training, plan to apply the process to a project shortly afterwards. Especially with a program like Revit, if you don’t start using and implementing the knowledge, you will not retain what you have learned.
2. Establish workflows and realize that these may not be the same for every project. Understand the benefits, but also know how to be efficient.
3. Seek out other professionals who are already using BIM for knowledge sharing; there’s no need to reinvent the wheel every time you run into a problem.
This is something HOK is currently implementing internally among their landscape architects. The teams make an effort to meet every three to four weeks in order to facilitate the sharing of ideas, content and workflows.