Manufacturer of LiveRoof^® Introduces a Planted Wall System Designed in Harmony with Nature

Green Walls Should Be Good for Plants: a Conversation with Dave MacKenzie

The team of horticultural scientists, landscape professionals, architects, roofing specialists and green building experts at Hortech, Inc. (Spring Lake, Mich.) who created LiveRoof^® — the green roof system proven in more than 600 installations — have launched a new planted wall system, LiveWall^®.  In this interview, Dave MacKenzie, horticulturalist and president of Hortech and its LiveRoof, LLC and LiveWall, LLC subsidiaries, discusses some basic questions about green walls and the new LiveWall system.

Q: First, what is the basic benefit of a green vegetative wall?

Transforming an ordinary wall into a vertical green landscape adds a living, organic element to a building. Green walls are visually appealing, inviting and inspiring, healthful, and beneficial to the environment (especially for moderating the urban heat island effect).

Q: What are the basic types of green wall systems?

There are trellis and cable systems and planted wall systems. With the first, a metal trellis structure or set of cables are attached to the side of building and support vines that grow from the ground up. Planted walls have soil (actually, an engineered growing medium) in a set of containers attached to a wall. Thus, planted walls provide soil for the plants all the way up the wall to the height of the installation.

Q: Vines… that prompts the question why not just grow ivy on a wall?

Ivy-covered walls are the most traditional form of green wall. As a horticulturalist and nurseryman, I am reluctant to speak ill of any plant. We grow and sell ivy. But English and Boston ivy both lack colorful flowers. And they can be temperamental and aggressive. In areas of cold winters, English ivy is prone to wintertime dieback. In warm climates, it can be a chore to keep it out of windows and siding. Boston ivy is more hardy but even more aggressive.

Even when vines are grown on a freestanding trellis or cables adjacent to a wall, vines have limitations when it comes to green wall aesthetics, design and function.

Q: Such as?

There is only so much creativity that a landscape architect can bring to a green wall design when constrained to using only vines. I mentioned the lack of colorful flowers with ivy. In addition, it can take years for vines to grow and climb up to make an entire green wall green. A planted wall can support a variety of plants — annuals, perennials, succulents, tropical plants and even herbs and vegetables — and can be a complete green wall from day one. Plus, with soil in all the containers all the way up the side of a wall, planted walls provide more shading and insulation for the building.

Q: When did you start working on a planted wall system?

Well, we started getting questions about green walls almost as soon as we introduced LiveRoof in 2006. We began formal R&D efforts on planted walls in 2008 and put four years of system evaluation and prototype testing into LiveWall.

Q: Why did you decide to develop your own planted wall system?

Because we could not find an existing system that was simple to install and plant, easy to maintain and change, and good at growing plants. The biggest surprise in our tests of current systems is that even many easy-to-grow, resilient, disease-resistant plants (like Hostas, Sedums, Alliums) kept dying. No matter what we tried in terms of irrigation, pruning or fertilization, we could not keep plants healthy in the systems we tested.

So, just like in our development of LiveRoof, we set out to bring our horticultural expertise to bear to understand the problems and design a better system to solve them.

Q: Your WallTers look like window boxes.

That was the inspiration. The idea of window boxes as the model for wall planters came up in our discussions with other horticulturalists, including Ed Snodgrass [internationally renowned green roof and vegetative wall expert and consultant] and David Fell at Hawaiian Sunshine Nursery, our licensed regional grower and distributor in Hawaii.

The reason that window boxes work so well is that they provide proper orientation for roots and stems and allow for irrigation like rain. The engineering challenge was to design a vertical system that could scale up and make it practical to install and maintain an entire planted wall with perhaps hundreds of boxes. That included devising a set of components to make it a complete system.

Q: What does LiveWall cost?

Of course, I have to say that it depends. For a professionally installed system, the price range is about $90 to $125US per square foot (depending upon the size of the system, local labor rates, and the type of plants). That is all-inclusive: green wall planning and design, pre-installation consultation and technical assistance, all the system elements and components (including irrigation), all the plants, delivery, installation.

Q: How is LiveWall distributed and serviced in Canada?

Just as with LiveRoof, we have a national network of licensed regional growers. In Canada that includes LiveWall Ontario (Mt. Brydges, Ontario), Pépinière Premier Plant (Saint-Sulpice, Quebec), Eagle Lake Turf Farms Ltd. (Strathmore, Alberta), and N.A.T.S. Nursery Ltd. (Langley, British Columbia). They can customize plant selection for every LiveWall project. They can deliver the module inserts abundantly vegetated with locally cultivated plants that are full-grown and flourishing for instant results and lasting beauty.

By Monica Karamagi

For builders, building green and reducing energy consumption must always be tempered with bottom line costs.

Fortunately, what leads to reduced energy usage and lower monthly utility costs for property owners can also mean reduced costs for builders. This is achieved when the builder takes a system-wide approach to energy efficiency.

When builders use a system-wide approach, the cumulative life cycle operating costs are lowered. This is because the building’s monthly operating costs are lowered. In this scenario, high quality mechanicals, smart control strategies and efficient lighting strategies are all key pieces of the puzzle, but energy efficiency really starts with the building envelope.

When builders think of the building envelope, they tend to think in terms of R-value, construction types, aesthetics and more recently, the total U-value and continuous insulation.

There is another aspect that is being recognized in contributing to the building envelope – air tightness. According to the U.S. Department of Energy (DOE), uncontrolled air leakage in a typical building can account for as much as 30-50 percent of a building’s heating and cooling costs. The reason is simple: every bit of outside air that enters the building through air infiltration must then be heated, cooled and/or dehumidified to get back to a thermostat’s set point.

Spray polyurethane foam (spray foam or SPF) insulation helps builders achieve air tightness goals. It acts as an air barrier, vapor retarder, weather resistant barrier and continuous insulation. It is also helps builders reduce material costs and HVAC (heating, ventilation and air conditioning) tonnage. Spray foam can also help builders achieve LEED^®  Canada(Leadership in Energy and Environmental Design) certification.

Material Costs

When a tight building envelope is achieved with spray foam insulation, builders often see reduced material costs across the board. Because closed cell SPF (typically used in Canada) provides an extremely high R-value (in the range of 15-16 cm), builders can meet R-value requirements using 2×4 stud members, as opposed to the 2x6s often required when insulation needs to be thicker to meet R-value requirements.

In addition to reducing lumber usage and costs, using 2×4 framing leads to savings on window and door extension jambs and provides additional square footage.

HVAC Reductions

Performance and design of mechanical systems must match the performance of the building envelope. With the energy reduction that tight buildings provide, HVAC systems can be significantly downsized, saving upfront costs. However, several other considerations must be made:

• Ventilation rates and strategy as “fresh air” is no longer supplied through the gaps and cracks in the building
• Use of sealed combustion or power-vented combustion equipment to prevent flue gas spillage and back-drafting
• Detailed sizing analysis (e.g., Manual J) to achieve a right-sized HVAC system that does not short cycle and ensures comfort, and minimizes upfront and operating costs
• Proper system design and equipment selection to ensure humidity control for comfort
• Good duct design to ensure sufficient air mixing and distribution

LEED Certification

Commercial and high-end residential buildings are increasingly designed with LEED Canada certification in mind. LEED assigns points based on energy savings, water efficiency, CO₂ emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts.

Spray foam insulation provides valuable points in several areas in the pursuit of LEED certification:

• High quality insulation
• Air tightness. A typical commercial building has air leakage rates of 0.017 to 0.045 cubic meters per minute (cmm) per square meter (sm) at a pressure of 75 pascals. ASHRAE defines a tight building as one with leakage rates of 0.003 cmm/sm at 75 pascals.
• Design flexibility to easily accommodate ducts in conditioned space

Spray foam can also contribute in less obvious ways. In the LEED Materials and Resources category, closed cell spray foam can assist in achieving points for material efficient framing. Closed cell spray foam increases the racking strength and facilitates use of wider structural member spacing.

When buildings are constructed with a system-wide approach, and given a tight building envelope, they can provide construction cost savings for the developer, as well as energy efficiency over the life of the building.

Monica Karamagi is the regional marketing and industry affairs manager for Huntsman Polyurethanes.  www.huntsman.com\sprayfoam.

LEED^® Canada is a registered trademark of Canada Green Building Council (CGBC).

By David Katz

Three recent events I attended have helped drive home the message that it’s time to move to the next level of building – having more structures meet the smart grid and be sustainable.

And that means taking a sustainable approach which requires a life-cycle evaluation of all the options; from aesthetics, to environmental, to smart grid integration benefits.

The three events that had the issue of energy as major themes were about Building Integrated Photovoltaics (BIPV), Building Envelope Solutions (BES) and Smart Grid Canada (SGC).

They looked at improvement to the building envelope, the addition of renewable energy and connecting to the smart grid. Key points made showed that, while there may be high initial costs, but there are definite, long-term benefits.  And that in order to attain sustainable – meaning GREEN, intelligent, smart, high-performance and net zero – buildings, an integrated design approach using life-cycle costs is required.

The BIPV event at Toronto Harbourfront showed the integration of photovoltaic in the beautiful façade artwork of Sarah Hall. The potential for more BIPV and the challenges of inclusion in the Ontario Power Authority (OPA) feed-in tariff (FIT) program were discussed. As we build and retrofit our buildings and energy grids to be smart, BIPV will be more prevalent.
A report by NanoMarkets, LC, a leading nanotechnology industry market research and analysis firm, entitled BIPV Markets-2011, showed the challenges and complexities for BIPV acceptance given the many different types, costs, and efficiencies.
The aesthetic concerns require the BIPV to be part of the building surfaces. The renewable electricity production should be measured, and not wasted, by overcoming inefficiencies in the building, considering its higher costs and possible financial incentives from the utilities and government that are paid for by all energy customers.
As a member of a building-to-grid (B2G) group developing the next smart grid roadmap, I am constantly trying to get the utility experts talking to the building experts so we bring down the silos of the past and develop the future integration of buildings and energy systems.
The smart grid efforts are focused on applying the information technology prevalent in our society today – as part of the electric, gas and water utility infrastructure – so the production, delivery and end use of these utilities will be enhanced and managed in real time. This will lower the rate of the increase in energy and water costs as the utilities replace the antiquated systems that currently have little information capabilities. They must be built to meet growing end-use demand.
At the BES event, a perspective on glazing and the update to the Ontario building code, with the significant energy efficiency requirements, was discussed.  And it was timely as recent incidents of falling glazing shows that safety must come first. The event provided presentations on fenestration but it also highlighted the convergence of the energy and building envelope objectives.
One new technology, electronically tintable glass, was presented by Helen Sanders, vice-president at SAGE Electrochromics, Inc.  In addition to the examples of facilities that were using the tinting glass to provide shading in real time as the sun moves across the sky, she showed a slide called the ‘Impact of Façade Technologies On Energy Usage in U.S. Building Stock’ from an LBNL report 60049, by Arasteh et al.

This showed the quads of energy use for heating, cooling and lighting for each façade. The most energy used was for the current building stock and average current windows that require the most heating and cooling energy.
It pointed out that less energy is required for low-E films and dynamic and triple pane units. There are significant energy savings in all three energy-usage examples with integrated insulating dynamic façades.
They showed how the technology works. As daylighting is recognized as the contributor to better occupant performance, the integrated building automation system increases natural light, reducing electric lighting, solar gain, glare and cooling while harvesting the daylight when available. It could also provide demand response capabilities when the grid is taxed by air-conditioning load.
Additionally, recent research studies by the Continental Automated Buildings Association (CABA) show that building automation has extended beyond the traditional heating and cooling controls to include the lighting, daylight harvesting, automated shading, and now tintable windows.
CABA’s ‘Bright Green Building’ report showed the convergence of the GREEN and intelligent building rating systems and how they complement each other.
Some of the challenges relate to the owners’ concerns about the perceived additional costs and how to pay for them. It should be noted that while renewable energy currently has higher initial costs, they are fueled by the sun, wind and water at little or no cost and provide environmental benefits.
The higher costs of the innovative building envelope technologies that provide long-term energy savings and production should be evaluated using life-cycle costs. Energy prices are rising. There are utility financial incentives to lower the initial cost and low cost financing available to make “bright” green buildings a reality.
There are many shading and other glazing options. Some are external to the building and they provide excellent opportunity to bring natural light into the building, while also being available to shield the building at times when the solar gain is extreme.
A case in point: Dr. Thanos Tzempelikos, M.A.Sc., Ph.D. recently performed significant energy modelling and produced a study called ‘The impact of Solarmotion-controlled exterior louvers and interior shades on building energy demand for different locations’ for Construction Specialties, Inc.
All in all, with these types of industry events and studies, it’s shown that a sustainable approach requires a life-cycle cost evaluation of all the options from the aesthetics, environmental and smart grid integration benefits.
So let’s have the buildings meet the smart grid and be sustainable.

David Katz is President of Sustainable Resources Management and a former Financial Evaluations Officer at Ontario Hydro where he applied life-cycle costs and multi-attribute scoring to major capital expenditure decisions. He currently consults to building owners and represents sustainable solution technology companies.  He can be reached at dkatz@sustainable.on.ca

Air leakage is responsible for a host of building problems: high energy bills, poor indoor air quality, occupant discomfort, wall deterioration (which is often concealed), and a higher carbon footprint. Until recently, owners of large buildings had few options at their disposal to test air leakage performance of their building enclosure (walls and roof) in a quantitative way.

Today, advanced technologies – a combination of sophisticated computer software, blower doors, pressure gauges and infrared imaging – is making it possible to actually measure full building air leakage performance, and start to pinpoint where the leaks are coming from. This information enables building owners to make informed decisions resulting in more efficient and durable buildings.

Case Study: The Ontario Association of Architects Headquarters

These new technologies were recently put to the test at the Ontario Association of Architects (OAA)’s Toronto three-storey headquarters where architect David Fujiwara is managing the Association’s building energy review and maintenance plan. As part of Fujiwara’s mandate to improve energy efficiency at the 20-year-old building, he engaged Halsall Associates to evaluate building enclosure air leakage performance.

Working with Building Science Corporation (BSC), Halsall conducted full building air leakage testing using a series of automated blower doors and pressure gauges controlled by a central computer. Halsall also used infrared imaging to scan for the source of air leaks. The testing was performed under the watchful eye of 30 guests, including OAA members, councillors and staff, who were invited for a first-hand demonstration.

How the test works

To test for air leakage, it is important to create a pressure-controlled environment. This means blocking off intentional openings in the walls and roof, that is, closing operable windows and doors, sealing air intake and exhaust vents, and shutting down all the building’s mechanical equipment. This preparation work is a big part of the process and results in trapping yourself – and in this case our 30 guests – in the building. Luckily, the first stage of testing took less than an hour and everyone survived the “lock down.”

Once the building is prepared, the testing works by using blower doors to force air in to, then out of, the building. This creates pressurized and depressurized scenarios which are then measured and logged. As the wind can affect building pressure, a baseline wind reading is taken on all the elevations before starting the test, in order to correct for wind effects.

The blower doors maintain a constant pressure within the building relative to the exterior. Since the building is not perfectly air-tight, air will leak through breaches in the wall assembly, usually at joints between different cladding components. The testing employs the basic principle that the air flow rate in through the blower doors will be the same as the aggregate air flow out through all the leaks in the building enclosure, and vice versa. Advanced computer software enables Halsall to check readings in real time. In the case of the OAA, for example, we could tell right away when a door was opened because the computer display  would show a sudden pressure drop.

The total air flow through the building enclosure can be expressed in a number of ways. We can divide it by the total wall/roof area to help compare the results to other buildings of different sizes (benchmarking). We can also convert the total air flow to an equivalent size hole through the building enclosure. This effectively combines the area of all the small holes and cracks into one aggregate hole, which helps one visualise the amount of air leakage.

For the second part of the test – to actually identify the air leakage locations – Halsall conducted a thermographic scan. The building is first scanned while the interior space is being pressurized, then again while undergoing depressurization. When the outside temperature is cool, so are the exterior wall surfaces. Interior air that leaks out will warm up nearby cladding components and produce a “heat signature” that can be detected with infrared equipment. The pressurized and depressurized scan results are then compared. As Halsall Project Principal Dave De Rose explained to the assembled audience, “If the hot spots appear the same under positive and negative pressure, this indicates a thermal bridge. If the readings are different, there is air leakage.”

How air tight is the OAA building?

If you add up all the small cracks and holes in the building enclosure, the combined hole is about one quarter of a square metre. In other terms this is the same as 0.91 L/s of air flowing through each square meter of the building enclosure when a pressure of 75 Pascals is induced across it.

On its own, this raw result may not mean much. But when benchmarked against industry guidelines, the OAA office building is performing well. The building has 30% less air leakage through the building enclosure than the US Army Corps of Engineers (USACE) standard. This is a very strict standard that governs construction of all new U.S. Army buildings. (See the graph for the full set of benchmarked results.)

The thermographic scan did, however, pinpoint a number of isolated areas throughout the building enclosure where air leakage is occurring. While these isolated leaks do not have a significant impact on the overall air leakage, these breaches could be contributing to local areas of concealed deterioration. Where there is air leakage, there is a greater risk of condensation, which can result in metal corrosion or mould.

The testing also showed that air leakage was occurring through the mechanical system dampers when they are in the closed position and around some of the dampers/ducts where they penetrate the enclosure. The impact of this air leakage is significant. The volume of air leaking through these components when they are closed was the same as 66% of the air leakage through the rest of the entire building enclosure.

What did the test results mean for OAA’s building management strategy?

The full building air leakage test provided the architect and building owners with accurate, detailed information to help them focus their building management strategy.

Given how air tight the building enclosure was shown to be, Halsall recommended against large scale building enclosure air sealing retrofits as this would result in only marginal gains in energy performance. Instead, we advised the OAA to focus on adjusting or replacing the mechanical dampers and on sealing isolated air leaks. This strategy is expected to have better energy saving results and also improve the building enclosure durability.

Air leakage testing helps owners understand their building. Knowing how your building is performing allows you to make educated management decisions and choose appropriate remedial actions. In short, you can plan for the right repairs at the right time. Conscientious owners who want to reduce their carbon footprint, improve occupant comfort, and protect their asset for the future should consider full building air leakage testing to find out how their building really stacks up.

Jake Smith is a Project Manager with Halsall Associates’ Restoration team. Halsall is a national building engineering firm with over 50 years’ experience in designing, evaluating and renewing buildings. Contact Jake at jsmith@halsall.com