This course is part of the Metal Architecture Academy

Photo courtesy of Brennan Photo + Video

Williston Basin International Airport was designed to be both people-centered and reflective of Williston Basin’s beautiful limestone and prairie landscape. It features 60,000 square feet of insulated metal panel walls (IMPs) that provide long-term durability, low maintenance, and high thermal capabilities—all of which support the health and comfort of travelers as well as contribute to essential sustainability goals.

A MULTITUDE OF BENEFITS: METAL BUILDING PANELS FOR WALLS AND ROOFS

A Brief History: How Durability Became Sustainability

Durability is defined as the power to withstand wear, pressure, and damage. Within the built environment, durability holds an even deeper meaning: it implies the building’s power to resist the forces of nature all around it over time—and without losing its structural integrity, essential function, and aesthetic goals. The building is a resilient structure, built to last.

It might seem more obvious today that a durable building would also provide environmental and cost benefits because of its inherent attributes. But durability has not always been a priority in the long list of considerations—even among those in the construction industry. According to the U.S. Environmental Protection Agency (EPA) archives, the green building movement sprung up in the 1960s and 1970s as a response to environmental movements and high oil prices, both of which spurred research on energy efficiency and renewable resources. For a few decades, the focus on green building was on minimizing energy and water use and reducing the use of excessive construction materials. Green building was sometimes seen as a niche approach, but as elements of durability have been included in its definition, it has become clear to many in the field that both environmental and durability considerations—together—constitute sustainability.

A building that has been designed to last for 60 years provides more resource advantages over a building built to last for 30 years, especially if indoor environmental quality (IEQ) and energy performance are comparable. The durable products and materials that compose the longer-lasting building will not need frequent replacements or repairs. Plus, the embodied carbon from, and investment in, the raw materials, as well as the energy and environmental impacts, are diffused over a longer period.

The idea is that the long life cycle of durability will usually make up for the environmental and economic deficits. Of course, this is a simplification, but it still provides a helpful way to look at durable products. There are exceptions and caveats that make durable (or resilient) design more complex—and for architects, more interesting. For instance, durable designers might also consider how a building will be assessed and used in the future. Why would they do this? If a building loses its value because it no longer seems useful or aesthetically appealing, it might be renovated or demolished—which means it never met its full life-cycle potential or paid off in terms of economic or environmental benefits.

Keeping this in mind, durable design could also include an element of foresight in which the architect selects materials and a design approach based both on structural resilience and the building’s usefulness. That might mean a design that features flexible spaces that can—rather than being scrapped—be converted to new uses in the future.

Metal on the Rise

Metal is a versatile building material, boasting both historical credentials and modern aesthetics. It has often been seen as durable and practical, a fine material for warehouses, but not always as a particularly “green” or especially beautiful material. Sustainability research and assessments have provided ways of measuring metal’s true role as an environmental asset. In addition, the metal industry has found new ways to manufacture metal for beautiful and modern designs, leading to the wide variety of applications it has today in commercial and residential architecture.

In recent years, metal has risen in popularity as a favored construction material. Beyond it being more accessible than ever, metal has a multitude of compelling qualities and capabilities that have earned it the right to rise to the top.

Those benefits include design aesthetics, energy efficiency, durability, fire protection, ease of installation, rainscreen installation capabilities, and the quality of being low maintenance. These benefits provide the means to achieve the important elements of the built environment: architectural vision and occupant health, safety, and well-being.

Metal Roofs

Many conventional roofing products, including asphalt shingles, contribute about 20 billion pounds of waste per year to U.S. landfills. Metal roofs, however, can often be installed onto existing roofs (depending on local building codes), eliminating the environmental impact—and costs—of disposal. Added to that benefit is the fact that metal roofs already exist as somewhat of an eco-product themselves because they are often made of recycled material.

Metal roofs have a variety of design options to fit nearly any architectural desire. Besides the wide array of colors, metal roofs can be specified in a multitude of shapes and profile configurations. They come as traditional standing seam profiles or can be manufactured to resemble shake, slate, shingles, or clay tiles. Let’s look at a few types of metal roofs and discuss their characteristics.

Low Slope Metal Roofs

Low slope metal roofs have a long history as a preferred covering for commercial, institutional, and industrial buildings. That’s because they are a high-performance, low-maintenance, cost-effective choice with practical capabilities: They protect against the elements and keep building contents and occupants dry.

As building owners and architects explore sustainable designs, low slope metal roofs are also appreciated for their many benefits, including long service life that saves money. Their low life-cycle costs, recyclability, light weight and other environmental qualities also provide significant advantages.

Photo courtesy of Metl-Span

Low slope metal roofs are the historical choice for commercial buildings because of their long service life, which saves money. Their low life-cycle costs, recycled content, recyclability, light weight, and other environmental qualities are appealing across the board.

Low slope structural roofing is usually used on roof pitches ranging from ¼:12 to 3:12. It consists of interlocking panels, called standing seam roofing, that run vertically along the roof surface. These panels generally come with a painted finish or a clear acrylic finish. All metal roofing used on low slope applications requires machine seaming during installation to ensure a watertight seal.

A seaming apparatus is placed onto the standing seam and run on top of the seam, seaming/rolling it to either a 90 or a 180-degree seam.

The standing seam design provides draining from rain and snow, eliminating leaks and ponding. The fact that low slope metal roofs are not prone to degradation like some other roofing materials means they are good in wet climates and achieve a long life span with low operating costs.

Steep Slope Metal Roofs

Steep slope metal roofs are defined as roofs with pitches of 3:12 or greater. They are known for both durability and aesthetics. In instances where a commercial building requires an attractive and affordable steep slope, this is the roof type building owners and architects often select.

Photo courtesy of ATAS International

Steep slope metal roofs are known for their eye-catching capabilities and often selected by architects for that reason.

They are also favored by environmentally sensitive building owners and architects who appreciate the roof's aesthetic appeal, long service life, low-maintenance requirements, light weight, and wind resistance.

For architects who want eye-catching design, steep slope metal roofs come in a variety of shapes and an array of coating colors. Their steep design accelerates the rate of water run-off, protecting them from debris, mold and mildew, and UV or acid rain degradation. The design preserves its aesthetic but also its life span, which has led metal roof manufacturers to typically warranty their products for 20–40 years.

Insulated Metal Panel Roofs

Insulated metal panel roofs, or IMPs, are an innovative metal roof product composed of interior and exterior steel facings bound to an insulating foam core. IMPs feature strong insulating properties, recycled content, a ridged feel, and a streamlined architectural aesthetic. The product has strong spanning capabilities and can be installed quickly.

IMPs can be installed on both low slope roofs and steep slope roofs for the benefit of commercial or residential projects. The product rates high on weathertightness and fire protection. And in terms of aesthetics, IMPs come in a multitude of colors to meet design goals.

Photo courtesy of All Weather Insulated Metal Panels

The insulated foam in IMP roofs provides weathertightness and temperature control, which is essential to places such as this winery. The standing seam roof creates a perfect platform for the solar panels.