ARE DONE YET?

MEASURING FOR A PROJECTS SUCCESS IS KEEPING CLIENTS AND DESIGNERS ENGAGED WELL AFTER INSTALLATION.

Landscape architects, like most people working on contracts, are used to fairly clear finish dates. Usually, their contracts with clients end with the installation of the landscape, and then there may be a year or two of care involved afterward.

But contract time periods may be getting longer, as clients increasingly begin to require ongoing monitoring and testing to ensure that their complex installations succeed. Designs these days involve more and more overlapping and intricate stormwater management, pavement, and irrigation systems. Plus, tighter client budgets may mean the planting of more young specimens rather than mature ones, so determining success may take multiple seasons, particularly with nonnative plants. Performance metrics that are written into contracts spell out what a client can expect after installation and increasingly prolong the contract period during which a landscape architect is involved.

"I like to compare the substantial completion issue to the commissioning of HVAC systems in the museums we do work for," says Eric Kramer, ASLA, a senior associate at Reed Hilderbrand in Watertown, Massachusetts. In this testing model, independent commissioning agents are brought in to work with the architects and mechanical engineers to ensure each building system works properly through cycles of seasons with periodic adjustments.

Kramer advocates that commissioning agents test landscapes, too. "Museums follow strict requirements for temperature climate control governed by system testing over time with mathematical models in place. In landscape architecture, we walk around and look at the trees, the grass, and other installations, and if they look according to our plan, we say it is done and hand it over to the owner. Thats not sufficient."

Robert Whitman, ASIA, a landscape architect at Gould Evans in Kansas City, Missouri, compares ongoing performance metrics to blood tests that many adults take yearly to assess their body health. "You may look fine, but you need those tests to assess the condition of your heart, kidneys, liver.... Its the same with perennials, turf, trees, and other living organisms," Whitman says.

For some landscape architects, their own physicals may be more common than tests specified in performance - driven contracts. Metrics that measure the ongoing permeability, structure, fertility, and biology of soil are often the province of agronomists. Tree metrics for twig elongation, caliper measurements, leaf color, and root growth are the realm of arborists. And the flow rates and infiltration of pervious pavement systems may trip off the tongue of some structural engineers, but not those of most landscape architects.

Yet advocates say landscape projects should undergo testing, not just once or twice but over periods of years. Maintenance manuals should spell out which tests should be executed and how, with clear illustrations. The manuals should be shared with maintenance contractors and testing specialists who will manage performance metrics over time. Specialists play a significant role in a performance - based model.

As the payoff, you get enhanced, long - term landscape performance and happier clients. Measuring plant growth will help protect an already substantial investment over time. Testing and monitoring will give clients some assurance of what they can expect years after initial installations. Developing a clear testing schedule in an illustrated maintenance manual can ensure clear expectations for maintenance contractors. And knowing plant metrics in advance of installation can ensure the right plant selections and plant viability over the long term.

One big challenge for postinstallation evaluations and metrics is getting the owner to pay for the work. But knowing metrics up front can have significant design payoffs, says Esther Margulies, ASIA, the managing principal of ValleyCrest Design Group based in Calabasas, California. "The paradigm shift from long - lived, water - loving ornamentals to lower water use and lower - maintenance native or adaptive plants may have an effect on plant life cycles," she says. "Lower

costs for trimming, fertilizing, and watering may more than compensate for shorter plant life spans. It would be great to see some metrics on native and adaptive plant life cycles in designed landscapes."

At the Clark Art Institute, in Wil - liamstown, Massachusetts, Reed Hilderbrand Associates is including performance metrics in nearly every facet of its landscape plan to unify the museums 142 - acre campus, a project at least five years in the making. The Berkshire Mountains site of this renowned art collection will be monitored and tested for its impact on stormwater, groundwater, and soil infiltration rates, among other elements. Now two years into construction, Reed Hilderbrands plan includes testing until the landscapes substantial completion in 2014. Additional monitoring and follow - up will be done by the museums maintenance staff and contractors after completion.

The project plan includes a central two - acre reflecting pool that the Pritzker Prize - winning architect

Tadao Ando envisioned as the key design element to unify the campus. When finished two years from now, the pool will unite two existing museum buildings of disparate periods with Andos new art gallery and visitor center design. Reed Hilderbrand also sees the central pool as an elegant means to measure the dynamics of water usage. "We want the pool to not just look like we designed it, but to work like we designed it," Kramer says.

The pool and its reservoirs are designed to manage stormwater surges and capture flows from foundation drains while they provide for irrigation, toilet flushing, and even water for chilling the HVAC so the Clark doesnt rely on the towns limited potable water sources. The integrated water use system will be tested to provide a detailed record of how water moves through the system at different times of the year —for example, when there are large irrigation draws versus when there are not. This recorded data will allow the weight given to the various uses to be adjusted seasonally or yearly as required to balance the multiple goals for the system.

In addition to water metrics, contract specifications include targets for the healthiest possible soil and call for measurements of its permeability and structure as well as fertility and soil biology. These measurements are to be taken over a 14 - acre site on the campus, where soils need to infiltrate at certain levels for the future viability of the lawn, grass, and meadow plantings and also as subgrade for the new parking lots, museum buildings, and driveways. With a lot of soil being moved around during construction, Reed Hilderbrand is testing soil both before it arrives on the site as well as once it is mixed with existing soil to ensure all areas will perform for whats designed. In addition, the building owner has an independent contractor on site to test all soil for proper compaction.

"As in HVAC commissioning, if adjustments need to be made to bring the systems into compliance, they should be completed before the owner accepts the project," says Kramer, who sees the potential for metrics and testing as going even further. He envisions turf and leaf samples that can be assessed for nutrient and moisture balance to show the function of the soils and planting system. He also would like to see the Clark monitor its stormwater management technologies such as the bioretention basins and pervious pavement system for capacity, flow rates, infiltration, and water quality. Soil stability and compaction rates could be correlated against use levels and weather conditions. While these have not been integrated into the Clark project, they are all areas of potential study.

Kramer hopes that a commissioning agent can be responsible for assessing all the landscape elements at substantial completion in 2014. An independent agent, working for the owner, could assess the function of overlapping systems —cMl, landscape, HVAC, irrigation —and recommend adjustments over the course of a full year, as well as train the museum staff to manage and maintain these systems. The selling point is that highly performing systems work better and pay for the interim cost of commissioning over time through re - duced maintenance costs, fewer plant replacements, and a more mature landscape that gives an institution like the Clark its identity and stature.

Landscape architects increasingly see the success of their projects determined over many years of vegetation establishment. Just as there are ways to measure engineered systems like those at the Clark, there are also ways to measure the long - term viability of plantings. The approaches are different but the point is the same: Substantial completion, in such a regime of measurement, becomes one step in a process rather than a clear finish line. Continued observation, monitoring, and warranties may help ensure the integrity of a landscape architects design, but the health metrics for plants arent frequently addressed or even very well understood.

"With performance - based criteria as your obligation, the client has a sense that plants are not just alive but are thriving," says Kelby Fite, an arbori - cultural researcher at Bartlett Tree Research Laboratories in Charlotte, North Carolina. "There may be a two - or three - year warranty for plantings on a project site, but what does that really mean to clients —that the trees are still alive?" Fite points out that its easy to keep a tree alive for a couple of years, but that scarcely fulfills a designers obligation to a client.

He adds that performance metrics can ensure that everybody understands the criteria for plants health, which helps avoid the finger - pointing that can go on around the quality of the plants brought onto sites. Performance metrics could include twig elongation or caliper measurements, leaf color, chlorophyll concentration or fluorescence, or even root growth.

"By saying at the start, This is what our expectations are and this is what our guarantee is, based on measurable things such as plant fluorescence values, clients have some assurance of what they can expect," says Fite.

Bartlett runs chlorophyll fluorescence tests on plants for one of its subcontracted nurseries before the plants are delivered to clients. The tests measure the efficiency of the photosynthetic process, helping ensure that only healthy plants are delivered. The tests bring a solid metric to the installation, a service that increasingly could provide a competitive advantage.

Proponents of performance - based models say the additional laboratory and time costs to test plant - growth metrics allow for measurements against ideal growth patterns that can be extrapolated from data already known about many species. Red maples, for example, are a species with a good body of scientific literature by arborists who have studied them for many years. How this species will respond to various environmental and cultural treatments can be extrapolated from those studies to set benchmarks for ideal performance. With a well - studied species like these maples, arborists can work with landscape architects to set up annual testing schedules and help calibrate a performance program.

However, for many species, ascertaining what the ideal growth metrics should be is a challenge. Research data on agricultural crops and even turfgrass is more robust than it is for most tree species, given how scattered trees of the same species may be versus the large field samples of a single crop such as corn or soybeans, or turfgrasses that can be studied en masse to predict behaviors.

Although comprehensive performance models are likely still years away, it is clear that landscape architects will increasingly need to be conversant in performance - based testing, whether to understand critical chemical and biological measures for plant establishment by species or to ensure the ongoing maintenance of increasingly complex built systems.

The concept of testing for performance isnt foreign: Landscape architects understand that technicians specify and test loading capacities for metals, absorption rates for stone, and physical and chemical properties of soils. But they dont often think about ways to specify and manage over time the more dynamic systems that define the profession or the performance metrics for individual plant species. However, as the Sustainable Sites Initiative, Leadership in Energy and Environmental Design, and other certification programs make sustainable site development imperative, how landscape architects think about metrics becomes more important.

Margulies, whose ValleyCrest Design Group integrates with her parent companys arborist, construction, and maintenance groups on many landscape projects, believes that moving toward a performance - based model is like a certification process. Both require certain metrics with a submittal of documentation over a period of time. Defining the metrics in a maintenance program is critical, and construction specifications must include quality - control benchmarks based on anticipated plant performance. These measurable benchmarks must be visible to the owner and whoever monitors the success of the project

In Marguliess ideal scheme, ongoing maintenance metrics would be set by a team of people: a landscape designer who can articulate the design intent over the long term; an agronomist who knows how to assess soil conditions at the right intervals; a certified arborist and a horticulturist who know the metrics for healthy plants and proper pruning schedules; and a high - quality maintenance contractor who can provide guidelines for fertilization, pest and disease control, and water and irrigation. "To create successful measurements over time, I want to know what you need to do weekly, monthly, and annually, and it cant be one persons vision alone of what will shepherd a young project into maturity," she says.

Few maintenance firms have a single employee who combines all of these specialized skills, so it is vital to establish a network of experts to address issues as they come up. Some specialties require sophisticated lab facilities beyond the capabilities of most contractors, so contractors generally call on independent specialists. Large owners, design firms, or landscape contractor firms frequently have a selection of subject matter experts they rely upon.

One concern is when tests show systems and plantings are not working as specified. How a landscape architect addresses the remedial work needed to bring underperforming elements up to specified standards has both ethical and legal liability dimensions, given that performance metrics are specified in a contract.

However, the concern is not so much to see flaws in the work but to ensure a process by which the landscape architect works as part of a team to ensure success in the long run.

"What we may now call substantial completion is really Phase i of a continuing evolution, and we need to consider that evolution as part of the design," says Whitman of Gould Evans. "We need monitoring and continuous evaluation of the landscape as we move forward. We need client education and construction and maintenance specifications as we go forward. And we need to think more about entire systems —not just individual plants —and the relationships of different sites to each other, not just from the design point of view but also in the maintenance." The results will be obvious to clients, Whitman says. "Its an investment that can only add to the value of the sites we work on."