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Keeping Promises: Exploring the Role of Post-Occupancy Evaluation in Landscape Architecture

How well do constructed landscapes live up to the lofty goals established by design professionals? And how do we know? Former CSI research assistant and University of Oregon graduate student Andrew Louw is investigating this topic for his masters thesis. He is both trying to understand the role of post-occupancy evaluation (POE) within the landscape architecture profession and exploring the use of a digital data collection method for POEs.


Though environmental, social, and economic performance goals are often identified during the pre-design and design stages of a project, most projects lack effective post-construction monitoring and observation to determine if, and how well, the project’s design goals are being met. LAF’s Case Study Investigation (CSI) program was born out of a need to encourage and support design firms in assessing performance and documenting the benefits of sustainable landscape projects. CSI is now in its fourth year, and leading firms are increasingly investing in in-house research. Yet  little is known about the use of and perceptions towards post-occupancy evaluation within the profession as a whole.

Louw believes a method known as Facilitated Volunteer Geographic Information (F-VGI), which is already used widely in the design process, may be well-suited for post-occupancy landscape performance analysis. The technology increases the capacity for analysis by crowdsourcing data collection to users, has relatively low cost, offers the opportunity for longitudinal study, and could be more objective than traditional methods since there is less chance for bias from volunteers.

Louw is evaluating Facilitated Volunteer Geographic Information (F-VGI) as a tool for POE by comparing it with traditional approaches like direct observation and intercept surveys. Using a LAF case study site, Central Wharf Plaza in Boston, he also sets out to develop a framework for using Facilitated Volunteer Geographic Information (F-VGI) for evaluating landscape performance.

Landscape architecture practitioners and others interested in landscape performance are invited to participate in Louw’s study by taking the following survey:

Please share the link with others!

Urban Green Space and Mental Wellness

May has been designated as National Mental Health Awareness Month to raise awareness about the importance of mental health to overall human health. Many factors contribute to mental health and wellness, including biological factors, experiences, and lifestyle, but the built and natural environments that surround us also play a critical role.

tkf-mental-wellness3Our friends at the TKF Foundation have worked with researchers Kathleen Wolf, PhD (University of Washington) and Elizabeth Housley, MA ( to produce Reflect & Restore: Urban Green Space for Mental Wellness, a research brief that draws on four decades of research.

The report is chock-full of evidence about the benefits of green space for mental wellness — from lowering stress to creating a stronger sense of community to reducing attention-deficit/hyperactivity disorder (ADHD) symptoms. The research brief underscores why even small bits of nature in the city are so important.

“The key message, confirmed by literally hundreds of studies, is that across all age groups, and in diverse cultural groups, there is a recurring positive response to small scale, often unremarkable, natural settings in cities. Some responses, such as mood change or a sense of relaxation may be personally felt, while other reactions, such as reduced blood pressure or cortisol levels, are happening at the subconscious level.”

Landscape architects are paramount in creating many of these green spaces, defined in the research brief as urban landscapes, gardens, parks or any private or public spaces where natural elements are key components. We’re checking and adding to make sure that all of the research cited is part of our Landscape Performance Series Fast Fact Library, where you can find over 120 statements of landscape benefits derived from published research addressing a range of environmental, economic, and social impacts. 

Landscape Performance at CELA

The Council of Educators in Landscape Architecture (CELA) Conference gets underway in Baltimore later this week, running March 26-29.

cela2014This CELA conference is the first to feature a Landscape Performance track with sessions that “explore the impact of landscape projects of various types and scales through the observation and measurement of environmental, economic and social benefits.” A total of 18 presentations and panels will be part of this track.

LAF will present during two Concurrent Sessions, serve as a Research Funding Workshop panelist, host a meet-and-greet for CSI Research Fellows and Landscape Performance Education Grant Recipients, and give updates at the CELA Board Meeting and Administrators Meeting .

Research from and about LAF’s Landscape Performance Series and Case Study Investigation (CSI) program will be part of four sessions:

Concurrent Session 1- Thurs, 8:00-9:30am

Presentations Based on 2012 and 2013 Case Study Investigation (CSI) Research

Presentations:    A ‘Texas Three-Step’ Landscape Performance Research: Learning from Buffalo
                              Bayou Promenade Klyde Warren Park, and UT Dallas Campus Plan
                              Taner Ozdil, PhD, University of Texas at Arlington

                              How Does It Change After One Year? A Comparison of Benefit Composition of
                              LAF’s Published Case Studies in 2011 and 2012
                              Yi Luo, Texas A&M University

                              Park Seventeen Residential Roof Garden: Landscape Performance and
                              Lessons Learned
                              Ming-Han Li, PhD, Texas A&M University

                              Assessing Residential Landscape Performance: Visual and Bioclimatic
                              Analyses through In-Situ Data
                              Bo Yang, PhD Utah State University

Concurrent Session 2 - Thurs, 11:00am-12:30pm

Waterfront Ecologies: Opportunities and Challenges of Assessing Site Performance

Panel with:          Kristina Hill, PhD, University of California at Berkeley
                              Mary Pat Mattson, Illinois Institute of Technology
                              Aidan Ackerman, Boston Architectural College

Concurrent Session 3 - Thurs, 2:30-4:00pm

Landscape Performance Series Case Study Review and Analysis: Strengths, Weaknesses, and Prospects

Panel with:          Heather Whitlow, Landscape Architecture Foundation
                              Mary Myers, PhD, Temple University
                              Bo Yang, PhD, Utah State University

Concurrent Session 4 - Thurs, 5:00-6:30pm

One Project at a Time: Measuring Social Performance for LAF Case Study Investigations

Panel with:          Katharine Burgess, Landscape Architecture Foundation
                              Elen Deming, PhD, University of Illinois at Urbana-Champaign
                              Taner Ozdil, PhD, University of Texas at Arlington

Vectorworks to Estimate Landscape Performance

By Doug Robb, MLA Candidate, University of Toronto

As landscape architects, we are faced with the challenge of situating our designs within a broader ecological and climatological context. A design proposal must invariably contend with the active forces of its environment, however these forces (such as rainfall, flooding, heat gain, wildlife migration, etc.) can be incredibly difficult to model through conventional CAD and BIM software. The strategy of simulation modelling is often employed, whereby multiple design iterations are compared and contrasted based on a standard rubric. Yet this form of exploratory design can be time-consuming, and is often problematised by the dual expectations placed on landscape architects to quickly represent their creative vision whilst simultaneously ensuring its performative functionality.

The Landscape Architecture Foundation (LAF) is continually looking for new tools and methods to evaluate landscape performance. LAF asked me to investigate how Vectorworks Landmark software could be used to estimate the performance of a given design. 

For landscape architects, the greatest strength of Vectorworks Landmark lies in its ability to handle a wide variety of filetypes, and to modify these external files through the built-in Site Planning tool sets. These tool sets are analogous to pre-defined CAD blocks which cater specifically to the require- ments of landscape design, from an extensive library of plant material and irrigation heads to site modifiers and grading tools. When used in tandem, these features allow a designer quickly to import a survey shapefile, modify the topography through massing models, hardscape, or planting, then begin to calculate site metrics such as runoff, cut and fill, and shading.


vectorworks-reportFor example, the Hardscape Tool Set can be used to assign different materials and classes to different components of a drawing. The software can then calculate site statistics, such as ratio of hardscape to softscape, site permeability, and potential runoff by “Creating a Report” and selecting from the preloaded lists of site metrics. Using this straightforward process, peak runoff rate can be calculated using the Rational Method. Vectorworks’ built-in libraries of blocks and calculation tools make quantitative landscape analysis easy and relatively straightforward. 

Currently, Vectorworks Landmark is a powerful tool for landscape architects to assess the impact of their designs upon the environment. In the words of Carl Steinitz, this design-led approach to project evaluation is useful for conducting site analysis and generating project metrics, however it is a somewhat limited strategy for generating future design possibilities. It would be tremendously useful if the rigorous analytical functions of Vectorworks Landmark were better able to foster a decision-based approach to landscape design. For instance, a number of possible design outcomes could be generated by limiting certain variables such as site permeability or shade cover. This feature is partially available through the intelligent Massing Model tool set, which allows for data-driven design by appending building data and code requirements to flexible massing models, however an equivalent for landscape performance is not readily available. This process would not only provide landscape architects with a wider range of design alternatives, but also encourage a more participatory design process with non-specialised stakeholders, such as environmentalists or community groups. 

While Vectorworks Landmark may not have the full capabilities offered by more specialized programs such as ArcGIS or Photoshop, its “jack-of-all-trades” approach to file management and site design makes it a powerful tool for the simulation modelling of multiple proposals within a single program. I believe this fast and flexible workflow is an invaluable tool for landscape architects who wish to efficiently test the environmental repercussions of their designs. In this sense, Vectorworks Landmark allows for the rapid prototyping of landscape futures as part of both a creative process, and an analytical device.

Landscape Performance Research: Monitoring Green Infrastructure in New York City

By Mary Nunn, RLA & Nandan Shetty, NYC Parks Green Infrastructure Unit

New York City is the densest city in America and as a result, largely impervious. The impacts of this are numerous, including combined sewer overflows, flooding, and damage of infrastructure and property. According to the Natural Resource Defense Council, the 100-year flood will occur as frequently as every 15 to 35 years in New York by the 2080s. Traditional wastewater infrastructure, such as overflow systems and treatment plants, comes at a high cost both financially and environmentally. In contrast, a green approach to addressing these problems — including green roofs, parkland bioretention systems, stormwater greenstreets, and right-of-way bioswales — supplies a myriad of social, economic, and environmental benefits in addition to managing runoff.

In New York City we are currently constructing hundreds of green infrastructure sites in the city’s most polluted “sewersheds”. The road to implementation remains perhaps one of the most challenging in the country, given the city’s degree of urbanization, physical and political complexity, and aging infrastructure. Given this, we have developed a university partnership model that aligns us with academics who are similarly motivated and interested in understanding these considerable challenges. Together, we undertand that green infrastructure is a new technology with many variables and unknowns. Our joint research challenge is to monitor performance, so that stormwater capture is quantified, cost effectiveness is known, and construction details and designs are constantly improved.

nashville-stormwater-greenstreetOur academic partners at Drexel University have used live tracking to monitor the performance of several constructed sites. At the stormwater greenstreet located on Nashville Boulevard between 116th Avenue and 209th Street in Queens (Nashville), 100% of stormwater runoff entered local catch basins and ultimately the combined sewer system prior to installation in 2011.

Over our 2012 monitoring season (April - November), we found that 21 out of 24 storm events were 100% retained within the site. During only three storm events, ponding inside the greenstreet caused brief overflows to the local catch basin. On an annual basis, the site’s performance suggests 74% - 86% retention of all rainfall over its catchment area, dependent upon annual precipitation variations. Furthermore, our data suggests that the Nashville site can retain 100% of the flow directed to it during all storms with less than 1.6 inches of rainfall.

In addition, Nashville was closely monitored during both Hurricane Irene and Superstorm Sandy, and it captured much more stormwater runoff than anticipated. Although the site was sized for a 5:1 ratio of catchment area to planting area, during Superstorm Sandy, inflow from the street was approximately 31 times direct precipitation on the site. Given the location of the site at a low point of the neighborhood, the increased ratio most likely occurred due to clogged drainage upslope. In total, approximately 40,000 gallons of water deposited by Superstorm Sandy either infiltrated into the site or evaporated.

We know that green infrastructure works, but there is much more to be gained by fostering a constant university partnership, especially given the scale of investment in these systems. A “design - build - research” feedback loop is requisite to monitor and learn how we can continue to improve performance-based green space.

Mary Nunn, RLA is a Landscape Architect with the NYC Parks Green Infrastructure Unit. At Parks, she has worked on a variety of projects citywide with an emphasis on sustainable design and stormwater management. Currently, she is responsible for the project management and design of green infrastructure systems in the Bronx River and Hutchinson River sewersheds.

Nandan Shetty is a PhD candidate at Columbia University, and has been working at NYC Parks Green Infrastructure Unit since 2008.  Nandan received a MS from Columbia University in Civil Engineering in 2013 and a BE from Dartmouth College in Environmental Engineering in 2008.