Versatility of Design and LEED Certification with Metal Composite Materials  

Image by Bob Perzel Photography

Boston University Center for Computing & Data Sciences, designed by Boston-based KPMB Architects.

Metal composite material (MCM) may be familiar to architects and designers for its versatility, durability, design flexibility, and dramatic beauty. However, the material’s sustainable characteristics and potential LEED credits—earned through the U.S. Green Building Council’s Leadership in Energy and Environmental Design rating system—should also be considered. LEED v4.1 prioritizes sustainable materials, helping manufacturers to design, produce, and deliver building materials that reduce a building’s environmental impact. LEED v4.1 also rewards manufacturers who reduce energy and water use during manufacturing, minimize their carbon footprint during distribution and transportation, and lessen overall carbon emissions through the entire production life cycle. LEED focuses on efficiency and leadership to deliver triple bottom line returns of people, planet, and profit. This course also discusses the history and manufacture of these leading-edge panels. It illustrates their features, benefits, and advantages, including an array of finishes that help MCM stand out from other cladding materials. This course emphasizes five significant projects targeted for LEED certification. The course begins by briefly reviewing potential LEED v4.1 points earned with MCM.

LEED V4.1 POINTS EARNED BY MCM

These are the main LEED v4.1 categories and credits that MCM products help to earn:

Category: Material & Resources

• Building life-cycle impact reduction: 5 points possible

MCM is recognized within the design and construction industries for its reduced life-cycle impacts. This credit intends to “encourage adaptive reuse and optimize the environmental performance of products and materials.” The two options are 1) building and material reuse for 1 to 5 points or 2) use of a whole-building life-cycle assessment for 1 to 4 points.

• Building product disclosure and optimization—environmental product declarations: 2 points possible.

With robust environmental product declarations, an MCM specification helps earn this credit. The intent here is “To encourage the use of products and materials for which life-cycle information is available and that have environmentally, economically, and socially preferable life-cycle impacts. To reward project teams for selecting products from manufacturers who have verified improved environmental life-cycle impacts.”

The two options include 1) environmental product declaration for 1 point or 2) a multi-attribute optimization.

• Building product disclosure and optimization - sourcing of raw materials: 2 points possible.

The documented sourcing of the raw materials used to create MCM is vital for earning this credit. The intent is “to encourage the use of products and materials for which life-cycle information is available and that have environmentally, economically, and socially preferable life cycle impacts. To reward project teams for selecting products verified to have been extracted or sourced in a responsible manner.”

The options include 1) raw material source and extraction reporting and/or 2) leadership extraction practices for 1 point.

• Building product disclosure and optimization - material ingredients: 2 points possible.

These LEED points are earned when specifiers select an MCM manufacturer with complete material documentation. The credit’s intent is “To encourage the use of products and materials for which life-cycle information is available and that have environmentally, economically, and socially preferable life-cycle impacts. To reward project teams for selecting products for which the chemical ingredients in the product are inventoried using an accepted methodology and for selecting products verified to minimize the use and generation of harmful substances. To reward raw material manufacturers who produce products verified to have improved life-cycle impacts.”

The two options include 1) material ingredient reporting for 1 point and/or 2) material ingredient optimization for 1 point, and/or 3) product manufacturer supply chain optimization for 1 point.

• Construction and demolition waste management: 2 points possible.

This credit intends to “reduce construction and demolition waste disposed of in landfills and incineration facilities by recovering, reusing, and recycling materials.” Options include 1) diversion for 1 to 2 points or 2) reduction of total waste material.

Category: Innovation

• Innovation: 5 points possible.

The innovation potential is a crucial benefit of MCM, as its unparalleled formability broadens creative design. The credit intends to “encourage projects to achieve exceptional or innovative performance to benefit human and environmental health and equity. To foster LEED expertise throughout building design, construction, and operation and collaboration toward project priorities.” Options include 1) innovation for 1 point, 2) pilot credit for 1 point, or 3) additional strategies that include innovation, pilot, and exemplary performance for up to 5 points.

HISTORY, FEATURES, BENEFITS, AND ADVANTAGES OF METAL COMPOSITE MATERIALS (MCM)

The International Building Code (IBC) defines a metal composite material (MCM) as:

A factory-manufactured panel consisting of metal skins bonded to both faces of a solid fire-retardant core. Section 1406 in the IBC focuses on the use of MCM in construction. The section contains considerable detail about physical and fire performance and the required testing to allow the use of MCM on various construction types.

History of MCM

While IBC Section 1406 has only been around since 2000, the use of MCM in North America dates back to the late 1970’s. The first aluminum composite material (ACM) was created in Europe in 1969. In 1979, the first ACM was produced in Benton, Kentucky. In the early 1980s, several global companies produced ACM and shipped it to North America for architectural projects. By the 1990s, three companies were manufacturing ACM in North America. Eventually, some manufacturers used alternative skin materials such as copper, zinc, stainless steel, and even titanium. This skin material change broadened the product name to metal composite material or MCM. Today, the number of manufacturers continues to grow worldwide, and the amount of variation in product offering and quality continues to expand.

One of the other significant variables seen in the industry over the years is the production process used to make the MCM. The typical method is to extrude or place a core material between two continuous skins of metal with a bonding technology to keep the components together, run the assembly through a series of heated rolls under considerable pressure, and end with the manufactured sheets cut to length. Continuous sheet production in a controlled factory environment has proven to be the most common practice to ensure the highest quality for MCM products.

Graphic provided by the MCM Alliance of the Metal Construction Association

The MCM production process.

Provided by the MCM Alliance of the Metal Construction Association

Section diagram of MCM.

Metal Composite Material Production

The MCM production process is relatively straightforward. It starts with producing an extruded core material, then applying a material that bonds the elements, and then adding aluminum skins for structural stability. This results in a product ready to finish in a myriad of colors and types. This material stack is heated and passed through a roll laminator, providing significant pressure and tension for bonding all the individual elements. The bonded sheets must be cooled in a controlled process to maintain the bond integrity and the material’s flatness as it cools. The semi-soft, malleable core becomes more rigid as it cools between the two metal skins. The skins, generally aluminum, are also at a high temperature, cooling as the process continues. Metal contracts as it cools, making the entire assembly want to move, twist, and bow until the finished composite sheet reaches ambient temperature. The required bond strength to keep the sheet together is not attained without the controlled addition of heat, tension, and pressure. The controlled cooling maintains the product’s flatness.

The critical attributes attained from the MCM production process are bond strength and flatness, making the panels aesthetically superior even after years of exposure. Based on many millions of square feet of experience, it was determined that a specific bond strength, both as-manufactured and after controlled exposure, was adequate to ensure that a panel would remain bonded over time. This performance value has been incorporated into the requirements used by major manufacturers and certification agencies to evaluate the acceptability of the finished MCM. Flatness is also a significant desired and sought-after property for MCM exterior cladding. This is defined in a white paper by the Metal Construction Association titled: “Visual Acceptance Parameters for Metal Composite Material (MCM) Panels and Panel Systems.”

FEATURES, BENEFITS, AND ADVANTAGES OF METAL COMPOSITE MATERIALS

Architects can choose from many cladding materials available in today’s market, so why choose metal composite material? This section provides an overview of the attributes and benefits of MCM. It is important to note that the material is created by a manufacturer and then fabricated for a project by a fabricator. The discussion begins with a notable project where metal composite panels figured into its LEED certification.

Anatomy of a LEED Project: Boston University Center for Computing & Data Sciences

The LEED Platinum-certified Boston University Center for Computing & Data Sciences, designed by Boston Architect KPMB, provides an exceptional workspace in a building that demands attention. Across 19 floors in 345,170 square feet, the $305 million center defies convention, forming an iconic landmark in the Central Campus. The cutting-edge design incorporates remarkable architecture, state-of-the-art resources, an environmentally friendly approach, and spacious, adaptable learning spaces.

The new center at Boston University is one of the greenest buildings in Boston, boasting 100 percent fossil fuel-free energy and unmatched energy efficiency. Designed to encourage collaboration, it delivers on its promise to students, faculty, researchers, and the environment.

The exterior profile captivates with cantilevers that soar above the campus and the Charles River, resembling a towering pile of books, as described by the leadership of Boston University.

Specialized Metal Fabricators fabricated, and Ferguson Neudorf Glass installed, 88,291 square feet of metal composite material in a bright mirror finish and a custom russet pearl finish to achieve both aesthetic and performance targets. The material is lightweight and durable, and consists of coil-coated and anodized aluminum sheets laminated on both sides of a fire-retardant core material. It is highly formable and integrates seamlessly into curtain walls, providing an ideal solution to this boundary-pushing build.

The anodized mirror finish offers the same reflective qualities, brightness, and transparency as conventional mirrors while being unbreakable and much lighter than glass or acrylic, and highlights the distinctive architectural features of the much-discussed exterior.

The project earned its platinum rating in LEED BD+C: New Construction under LEED v4. The credits that may pertain to its MCM content include:

Category: Material & Resources

• Building life-cycle impact reduction: 3 points of 5 possible
• Building product disclosure and optimization - environmental product declarations: 1 point of 2 possible
• Building product disclosure and optimization - sourcing of raw materials: 1 point of 2 possible
• Building product disclosure and optimization - material ingredients: 2 points of 2 possible
• Construction and demolition waste management: 1 point of 2 possible

Category: Innovation

• Innovation: 5 points of 5 possible

(For an accounting of all points earned, go to: https://www.usgbc.org/projects/boston-univ-computing-data-sciences?view=scorecard.)

Image by Bob Perzel Photography

Boston University Center for Computing & Data Sciences, designed by Boston-based KPMB Architects.

MCM BENEFITS AND ATTRIBUTES

The specification of MCM brings these benefits and attributes:

Formability Inspires Creative Designs

Being formable and versatile, metal composite materials can achieve sweeping curves and tight radiuses and can perfectly adapt to a building’s contours. Brick, stone, and wood cannot be shaped with the same ease. Because of these attributes, MCM encourages innovative architectural design.

Lightweight

MCM is lightweight and thus is easier to transport and handle on-site. It places a reduced load on the wall framing and foundation (brick, stone, and solid plate weigh more). The lightweight MCM reduces the dead loads on structural members, saving construction costs.

High Rigidity

MCM also provides high rigidity. Due to its composite structure, it achieves a high strength-to-weight ratio, allowing for large panel sizes. It is durable, stable, and can be perfectly formed without any loss of rigidity.

Oil Canning

MCM panels keep their shape and remain flat, even when exposed to extreme temperature changes. Flatness is critical; architects must specify the correct material to avoid oil canning. The degree of oil canning and the appearance of the sheets will vary depending on factors such as the length and color of the panels, alloy, gauge, galvanizing process, substrate condition, and exposure to sunlight. Metal composite material panels are naturally flat and provide the lowest risk of oil canning.

Reflective

MCM is reflective (of both heat and light), potentially reducing the thermal loading on a building. Special “cool” paint finishes can increase this reflectivity.

Weather/Corrosion Resistance

MCM does not degrade in harsh environments. Select finishes inhibit corrosion in the harshest conditions, such as along coastlines with wind-driven salty air vapor.

Affordable

Large panel sizes and prefabricated panels provide fast installation at a lower cost. Depending on the project location, complexity, panel sizes, and attachment system, the estimated installed cost ranges from $30 to $80 per square foot.

Temperature Resistive

MCM products withstand environmental temperature changes from -55 to +175 degrees °F (-50 to +80°degrees Celsius). The coefficient of linear expansion is governed by the aluminum sheet. A 10-foot panel could expand 3.5 millimeters or 0.14 inch over a 90-degree°F temperature range.

Perforation

MCM has perforation capabilities. Perforation patterns can be geometric, slotted, or customized. Holes may be punched or routed by computer numerical control (CNC). Perforated panels are ideal for a variety of applications, including parking garages. Note that perforation is not the MCM manufacturer’s responsibility or capability, but it belongs to the fabricator.

LEED Project: MCM Panels Help Bring About a Unique Design Serving a Purpose

Chicago is renowned for its skyscraper architecture, and the city’s LEED Gold-certified Tower Hospital at Rush University Medical Center, designed by Chicago-based Perkins+Will, stands tall among the best. Rush University and the city of Chicago praise the new 840,000-square-foot project. It has won numerous awards and accolades, including Engineering News-Record Midwest’s Project of the Year (2012) and the 2013 MCA Chairman’s Award in the Institutional Project category. KPMG named the Rush Tower “one of the most innovative and inspiring urban architecture projects in the world.” The Chicago Tribune architectural critic Blair Kamin called it a “towering achievement; the new Rush Hospital could be Chicago’s next great building.”

More than just a pretty building, it was designed by and for its occupants—the doctors, nurses, staff, and patients who use it. The unique butterfly-shaped design is awe-inspiring to outsiders, but the design also serves a practical purpose. The floor plan, essentially a triangle, brings the patient rooms closer together, a specific concern for the nurses seeking more efficient access to patients. “We used an inside-out approach to design Tower Hospital,” said John Moorhead, senior project designer at Perkins+Will.

The architects collaborated with Rush staff to find out how they worked and designed the shape of the building to fit their operational model. “We let that impact what the design needed to be,” Moorhead said. “The nurses talked about the number of miles they walk per shift. They were particularly interested in creating a plan that pushed together the patient rooms.”

Once the butterfly shape was conceptualized, the challenge became how to make it fly─functionally, aesthetically, and monetarily. An aluminum composite material provided the solution. About 250,000 square feet of MCM in a custom bone-white color was installed as exterior wall cladding on the Tower Hospital. “Metal provided flexibility and affordability,” Moorhead said. “It was the perfect choice to give the crisp white look that Rush was interested in, and it was easily adaptable to the curvilinear shape of the building.”

The aluminum composite material used to clad the tower helped Rush realize those goals. The material is durable and can be bent into any shape. It was noted that the Rush Tower has a lot of bends and curves, and the MCM panels provided the vehicle for architects to employ.

Sobotec in Hamilton, Ontario, the metal fabricator on the project, designed a unitized curtain wall system to enclose the Tower as quickly as possible. Sobotec created AutoCAD computer-generated drawings to fabricate the MCM panels. ASI Ltd., in charge of the installation, then fit the panels into the prefabricated curtain wall with a framed support system for the metal panels and glass.

Like many academic medical centers, the Rush campus is a conglomeration of buildings constructed during different decades. The campus has several metal buildings, so an aluminum composite-clad tower would feel cohesive. The Rush leadership, Moorhead explained, “really wanted to project an image of fresh, clean, modern, and technically savvy.”

Robert R. Gigliotti; courtesy of 3A Composites USA, Inc.

LEED Gold-certified Tower Hospital at Rush University Medical Center, designed by Perkins+Will.

HIGH-TECH FINISHES PROVIDE A MODERN IMAGE

It is essential to specify the right finish for the project. Considering coastal or chemical influences, positioning of the sun, and desired appearance factor in determining the correct finish for the application and warranty considerations.

A Variety of Finish Options

• Polyvinylidene fluoride (PVDF): Due to its durability to withstand harsh climatic conditions, 70 percent PVDF resin-based coatings are used worldwide. Paint containing 70 percent PVDF can resist chalking and fading and withstand lengthy exposure to UV rays, temperature, humidity, water, and atmospheric pollutants like acid rain.
• Fluoroethylene Vinyl Ether (FEVE) clear coats: FEVE clear coats are often used on bare finishes (such as various brushing patterns). It offers protection from the elements to preserve the aesthetic of the bare finish. This clear coat provides transparency to observe the natural brush strokes applied to the coil. Various tints can broaden the color palette and improve the project’s aesthetics.
• Silicone-modified polyester (SMP) and highly-durable polyester (HDP): Highly-durable polyesters have improved formulation, resulting in significantly improved durability and color retention with greater UV degradation resistance. They are often used in exotic finishes, such as color shifting and textured finishes.
• Custom colors: Manufacturers typically have a color-match department specializing in color development to help guide architects/designers through the process. Suppliers can match most Pantone, RAL, NCS, or other paint manufacturers’ systems. This flexibility with paint manufacturers for brand identity custom colors is an added advantage.
• Patterns that mimic natural surfaces and metals These include stones, woodgrains, abstracts, graphite, stainless, zinc, mica, and metallic.
• Anodized: Anodizing is an electrochemical process that thickens and toughens the naturally occurring protective oxide on aluminum. The anodized finish becomes part of the metal, and its porous structure allows for coloring and sealing. Aluminum oxide is one of the hardest surfaces known, second only to the diamond.
• Brushed and mirror finish: A brushed finish provides warmth and richness and offers an alternative to a colored opaque finish. However, it may lack color consistency from batch to batch and is not recommended for coastal or harsh chemical applications. Reflective mirror sheets reflect the natural environment without the higher weight and breakability of glass.
• Color-shifting paints: Color-shifting materials, originally derived from the automotive industry, change color as different wavelengths of light are reflected back to the observer. Depending upon the viewing angle, the panels offer ever-changing color gradients with iridescent highlights. The color effects are enhanced as the individual surface layers break up and refract the light. Typically, two or three colors are selected with one opposing color from the color wheel selection.

An MCM representative can help determine which finish option is best for a project based on the location and application.

Mark Kempf Photography; courtesy of 3A Composites USA

Exo apartments in Reston, Virginia, designed by R2L: Architects in Washington, D.C.

LEED Project: Color-Shifting Aluminum Composite Panels Complement Dynamic Windows

Marketing materials for the Exo apartments—which feature a gleaming contemporary facade—encourage residents to “live in full color” in this 457-unit multifamily residential community that was targeted to achieve LEED Gold status. Located in Reston, Virginia, Exo residents live less than 25 miles from Washington, D.C.

The Exo aimed toward LEED status by including sustainable building materials and techniques, including smart glass technology. Recyclable MCM panels manufactured with post-manufacturing and post-consumer content contributed LEED credits.

The 530,000-square-foot Exo comprises two identical 16-floor towers connected with a single-story reception-area link building. It is clad in aluminum composite material in a color-shifting finish. The MCM product was selected as a complementary building material to Exo’s color-changing smart glass technology, which adjusts window tint to allow optimal natural light.

R2L: Architects was tasked with designing Exo for Greystar as the first multifamily residential community in the United States to feature a particular brand of dynamic glass. “Our design was driven by smart glass technology,” said Sacha Rosen, AIA, principal, R2L: Architects. “This was to be a world demonstration project, serving as the first all-residential building using (this brand of dynamic glass). Incorporating smart glass technology required an extensive design process.”

The pre-glazed windows use electrochromic technology, requiring wiring to each window for electrical control. Apartment residents can control the windows in their apartment through an app that lets in natural light while reducing glare, lowering energy costs, and eliminating the need for shades or curtains. Apartment managers also have access to overall building control for the windows.

To aid in this intricate window design, Custom Walls & Windows, Inc. of Jessup, Maryland, began work with general contractor John Moriarty & Associates of Virginia, LLC, based in Arlington, and R2L: Architects in early 2017. “It was Custom Walls & Windows’ suggestion to clad the building with (the aluminum composite) panels,” said Rosen. “The thought was: If the glass changes colors, why not use metal panels that change colors?”

The project features 150,000 square feet of MCM in an ocean-toned color-shifting finishing system. The colors are transitional finishes that celebrate the natural color shifts that occur in the world around us. From naturally occurring elements to the glowing luster and sheen found in modern metals and luxury goods, colors add biophilic fascination to the built world.

As the original aluminum composite material, this brand allows architects and designers to meet the fire performance requirements of today’s building standards. Consisting of two sheets of smooth 0.020” aluminum heat bonded to a solid, fire-retardant core in 4mm nominal thickness, the MCM system is one component of the wall assembly that meets the requirements of fire classifications while offering the proven product properties such as flatness, formability, durability and ease of fabrication.

“The color of the overall design was generated by the smart glass, so the cladding color had to look good with the glass,” according to Rosen, who said the smart-glass technology offers residents four tints ranging from clear to darkening shades of blue. “Custom Walls & Windows suggested the (ocean color). The color was perfect, so there was no need to pursue custom colors.”

The Exo’s twin 16-story towers rise above a landscaped parking plinth featuring 646 parking spaces and are connected by a link building designed completely in intelligent glass. According to an architect’s statement, the building facades are modularized and designed to leverage efficiencies in fabrication and construction, while scattered balconies punctuate the elevations.

The box-like design of the residential towers may be straightforward, but according to Rosen, the color-changing building materials make it stand out. “There are so many new developments on the market in the Washington, D.C., area, you have to differentiate your offering,” Rosen said. “The Exo is very contemporary and different from everything else out there. We used the building materials to make it striking.”

Approximately 16,000 panels were fabricated and installed with a male/female interlocking system. Custom Walls & Windows designed a three-piece panel system with glass and panels for easier installation. “The (aluminum composite panels) look fantastic,” Rosen said. “It’s even more intense than I had hoped. It’s very striking and contemporary. Often, you have a vision for a design and then have to figure out how to make it a reality. It’s very rewarding as an architect to have access to a unique and special material…and to work with a contractor who knows how to use it.”

SUSTAINABILITY AND HOW MCM HELPS EARN LEED CERTIFICATIONS

This section discusses how MCM is a sustainable product, beginning with its manufacturing process. After that, the discussion turns to a brief review of specific LEED points that pertain to MCM.

Photo courtesy of CEI Materials

Residence Inn Marriott Boston Watertown, designed by Stantec Architecture.

Manufacturing Environmental Impact

During the manufacturing, all excess material is recycled back into the process. Scrap aluminum goes back to aluminum processing plants for recycling, and the scrap core material gets recycled.

Composite Concept

The sandwich concept reduces energy input and consumption. Given that aluminum, the most common metal used in MCM, requires large amounts of energy to be produced, the portion of aluminum used to manufacture MCM is by far less than that of flat sheet aluminum. Typical MCM uses 70 percent less aluminum than 1/8-inch plate.

Coil Coating Environmental Impact

The continuous coil-coating process provides MCM with a protective coating that is available in a wide range of paint colors and finishes. During the coil-coating process, 99.9 percent of all volatile organic compounds (VOCs) are captured. Excess paint is recovered and used to cover the non-visible side of MCM, so no excess paint is burned as waste. Additionally, all solvents used to clean the machinery are collected and reused.

Seventy percent PVDF resin-based coatings are used around the world on the exteriors of numerous architectural projects because they can:

• Resist chalk and fade
• Withstand lengthy exposure to:
• UV rays
• Temperature
• Humidity
• Water
• Atmospheric pollutants, like smog

Aluminum Environmental Impact

In the wake of the green movement, there is an increase in demand for energy efficiency from consumers, as well as regulations and mandates set by the government.

Aluminum plays a crucial role in the sustainability of new buildings and the renovation of existing structures. Due to its performance properties, aluminum largely contributes to new buildings’ energy performance, safety, and comfort. It also plays an essential role in producing renewable energy from solar sources.

Aluminum’s ability to reflect 95 percent of solar energy significantly reduces cooling costs; energy efficiency is a key qualifier for LEED building standards.

Recycling Process of Metal Composite Material

At the end of its very long lifespan, MCM’s aluminum is 100 percent recyclable without losing its material properties. This is in contrast to recycling other materials, such as plastic, which can lose the strength of its properties during the recycling process.

Environmental Product Declaration (EPD)

An EPD offers a standardized, internationally recognized way to evaluate and specify a product with a low environmental footprint. An EPD can be produced for one specific manufacturer’s product (proprietary EPD) or for a particular product type (industry-wide or generic EPD).

EPDs are created using life-cycle assessment (LCA) data specified by the product category rules (PCRs) and based on ISO 14025 standards. PCRs determine product information collected and define the type of LCA data to be evaluated. EPDs are included under LEED v4 in the Materials and Resources category criteria—Building Product Disclosure and Optimization—Environmental Product Declarations.

Metal composite material manufacturers that hold EPDs have invested time and money in gathering LCA information. This information is useful for identifying processes and ingredients that negatively impact the environment and human health. Architects can use this information to look for evidence of improvement in the environmental impact of a product across its life span. The LCA information identifies what the company acted upon and what positive changes an MCM manufacturer has made.

Using an EPD to compare the environmental impacts between the same or similar products can be tricky since few are available where the same PCR has been used, with the same life-cycle phases evaluated. However, they can start a discussion about a company’s sustainability goals.

LEED v5 in 2025

The latest version of LEED should be rolled out early in 2025. The key goals of the new LEED v5 for BD+C are:

• Decarbonization
• Quality of life
• Ecological stewardship

The first public comments on the new version occurred in April and May 2024. The second round of public comments occurred in September and October of 2024.

Some of the categories in LEED BD+C: New Construction v5 may include:

• Climate Resilience Assessment
• Human Impact Assessment
• Carbon Assessment
• Integrative Design Process
• Compact and Connected Development
• Electric Vehicles
• Equitable Development
• Sensitive Land Protection
• Transportation Demand Management
• Minimize Site Disturbance

Though the new LEED version will be released, projects can still use the current LEED v4.1. At this time, there is no date planned to sunset v4.1

Mark Kempf Photography; courtesy of 3A Composites, USA Inc.

C.H. Robinson flagship operation, designed by Skidmore, Owings & Merrill.

NOTEWORTHY PROJECTS WHERE MCM HELPED ACHIEVE LEED CERTIFICATION

Several LEED-certified projects with MCM panels have already been presented in this course. Here are a few more:

LEED Project: Wide Array of Metal Exterior Components Used in LEED-Certified Design

The LEED Silver Residence Inn Marriott Boston Watertown is the first hotel built in the area in 50 years, Dana Forsythe of the Wicked Local Watertown explains. The hotel is a joint venture between developers Boylston Properties of Boston and Stonebridge Companies in Denver. Boylston is known for its recent projects in developing areas of Boston, such as the recently completed LINX and the $60 million corporate development in Watertown.

The Residence Inn Marriott is located in Watertown’s East End. William McQuillan, Principal of Boylston Properties, said, “We built a contemporary building on purpose that has a 24/7 life to it. It’s about the future of Watertown, and it’s one of a number of projects going on in the East End that are all about the future of Watertown.”

Stantec Architecture designed the hotel, which sits in the location of the former Charles River Saab, the oldest Saab dealership in the United States. The 108,000-square-foot hotel features abundant, sustainable amenities contributing to its LEED ranking, including energy-saving HVAC, lighting, and groundwater systems. Additionally, a range of sustainable construction processes was also adopted.

According to the general contractors at PROCON, “The building’s exterior was a combination of color reflective masonry and panels with lighter toned upper floors highlighted by recessed faux wood accents.”

Using a drained, rear-ventilated rainscreen system, CEI Materials fabricated the metal composite and aluminum plate components of the facade. This system offers rainscreen technology with varying joint widths and color versatility. “With ten different colors on the project, joint colors and color layout of the panels required special attention in the final design and fabrication and installation,” said CEI Materials Project Manager Nick Sodt.

CEI fabricated 45,000 square feet of metal components for the project, which saw a few challenges, such as the site access on Arsenal Street due to existing power line layouts. Additionally, the company fabricated large 14-foot by 16-foot panels for the exterior, which created some challenges in terms of shipping and installation that were overcome.

The six-story hotel was a welcomed addition to the area, offering 150 spacious accommodations ranging from studios to two-bedroom suites with fully equipped kitchens. Guests can enjoy an array of modern conveniences, including an indoor saltwater pool. Watertown in Greater Boston is becoming highly popular with new sustainable developments that breathe new life into the area.

LEED Project: Metal Fins Reflect Water Movement and Reduce Glare in an Energy-Efficient Riverfront Office Building

The Chicago flagship operation of logistics provider C.H. Robinson, which aimed to achieve LEED Gold status, opened its doors to employees in August 2018 as the first anchor tenant in the new Lincoln Yards revitalization development near Chicago’s Lincoln Park neighborhood. Designed by the Chicago office of architecture and engineering firm Skidmore, Owings & Merrill LLP (SOM), the new four-story office building in 207,000 square feet accommodates more than 1,000 employees of C.H. Robinson, a leading global third-party logistics provider. This modern office building reflects its riverfront location with a design that emulates the flow of water with undulating fins fabricated from aluminum composite material.

To help achieve a LEED certification, the building incorporates low-cost, high-efficiency materials to achieve significant performance improvements, according to an architect’s statement. It is clad in heat-reducing glass shaded by the MCM fins, designed to mitigate solar gain, reduce glare in workspaces, and increase daylight in communal areas.

The recyclable MCM—manufactured with post-manufacturing and post-consumer content—contributes LEED credits to building projects. The undulating fins were fabricated with approximately 28,240 square feet of 4mm MCM in a custom silver mica color.

“SterlingBay presented us with a challenging and exciting opportunity that we tried to resolve with a sophisticated but simple design concept,” said Jorge Rovira, AIA, associate, SOM architects. “They asked us to create a design that would integrate the building with the river and that could be built efficiently,” Rovira said. “We investigated a mix of high-performance building materials to achieve LEED certification. When we looked at the big picture for this design, we knew we wanted to bring light deep inside the space while maximizing sustainability by controlling daylight to create a better workplace. We introduced the idea of large ‘fins’ that would be shaped to reduce glare inside and offer an opportunity to reduce the window-to-wall ratio and incorporate more surface for insulation. Behind the fins, a well-proven unitized curtain wall would provide the enclosure.” These fins would be designed with profiles that would move in and out from the building to meet changing glare control requirements, according to Rovira, who said the fins would also create the perception of long waves and reflect the movement of the river.

SOM engaged the engineering expertise of Sobotec Ltd. (www.sobotec.com), of Hamilton, Ontario, Canada, to work together to turn the vision for the facade fins into reality. “When we were thinking about a metallic surface, we thought (MCM) would be cost-effective and easy to handle and could be formed into different shapes. We were able to introduce a unique central atrium to bring more daylight into the building and yet remain within the project’s budget because we saved building material costs by selecting (the MCM). We were quite comfortable using aluminum composite material because we knew it could be twisted and that the corners would be sharper than those created with metal panels,” said Rovira. “We wanted the brightness of silver and its reflection,” he continued. “When light hits the silver (panels), it looks even brighter and almost gleams in the sun. As light hits the Chicago River, it bounces back so that you can see the river reflected on all floors of the building. The sparkling reflections and water movement are very beautiful.”

Sobotec engineered and fabricated approximately 300 different panel shapes to create the sunshade design on each of the building’s four floors, with one identical pattern repeating on the second and fourth floors and another on the third floor and roof. Each elevation features unique panels that create an angled facade and contour look for the fins.

Sobotec fabricated the panels and gussets and installed them in a unitized system in the controlled environment of the company’s shop rather than in the field. The units feature a custom aluminum frame and hook and pin system with locking bars. A total of 827 finished units measuring approximately 5 feet wide by 6 feet tall were shipped to the site for installation.

SOM architects spent approximately one year designing the project; construction was completed in one and a half years. Now that building construction is complete, “we all agree that it looks fantastic,” according to Rovira. “It’s a simple yet elegant design.”

CONCLUSION

In summary, let us review the potential for LEED credits and creative flexibility with the specification of metal composite materials. In the LEED v4.1 rating system, MCM excels in two categories: Materials & Resources and Innovation. Points earned with MCM focus on building materials that reduce a building’s environmental impact. LEED also rewards manufacturers who minimize energy and water use during manufacturing. The overall effect is a lessening of carbon emissions through the entire production life cycle. MCM specification often leads to Innovation points because of the material’s formability, flexibility, and high-tech finishes. These characteristics enhance creative potential, as illustrated in several highly regarded and visible projects where MCM added to the project’s aesthetics and helped achieve LEED certifications. The section on the manufacturing process of MCM helps explain the product’s lightness, durability, and resistance to oil canning. All these factors make MCM a logical and desirable cladding choice for architects and designers seeking an innovative material that helps achieve a LEED certification.

Kathy Price-Robinson writes about building and design. Her “Pardon Our Dust” remodeling series ran for 12 years in the Los Angeles Times. She specializes in writing about buildings that are durable and resilient to climate disruption and products and designs that provide shade in hot climates. www.www.kathyprice.com