CONCRETE

Research Center ICTA-ICP, Barcelona, Spain, by H Arquitectes and DataAE

The material strategy of the Research Center ICTA-ICP forms a dialogue between the permanent and the ephemeral, achieving ambitious sustainability goals through the interaction of these extremes. The translucent and dynamic “bioclimatic” façade wraps the robust concrete structural frame to create a durable, adaptable, natural-driven, and human-centered research facility. The concrete frame creates four interior courtyards for passive light, natural ventilation, and social interaction. The Research Center ICTA-ICP balances a robust and durable concrete frame with less permanent building systems to provide a long lasting yet adaptable research facility.

The architects describe the concrete frame as “long life, low cost, and high inertia.” It acts as a thermal mass retaining heat in the cool weather and absorbing heat in the hot weather. An active radiant system embedded in the floor slabs augments the passive performance by coupling the slabs with the earth. Liquid is pumped into tubes buried deep in the ground where the temperatures are nearly constant, and then then it is pumped through tubes embedded in the concrete floors to moderate the interior temperature. Dimples in the concrete ceiling increase its surface area for energy exchange, and diffuse acoustic reflections.

The bioclimatic façade protects and leverages the mass of concrete for luminous and thermal comfort. Louvers automatically open to allow natural ventilation and close to preserve the heat within the concrete frame. The façade’s transparent polycarbonate skin invites natural light through the exterior walls and into four courtyards from the translucent roof above.

In contrast to the robust concrete, the interior partitions and the building envelope use light materials with lower embodied carbon, anticipating future changes in use and other adaptations throughout the long life of the structure. Plywood boxes define the interior rooms, creating a warm, less precious, and quasi-finished expression of impermanence and change over time.

The building creates three distinct interior climates, to save energy and offer people delightfully dynamic environments, a concept known as alliesthesia. First, the unconditioned public atria and circulation spaces experience the widest range of temperatures and light levels. Second, the naturally ventilated offices that sit between the exterior skin and the interior atria are tempered to a narrower range of conditions. Third, conventional mechanical systems fully condition the research laboratories for both comfort and safety.

STEEL

United States District Courthouse, Salt Lake City, Utah, by Thomas Phifer and Partners

The United States District Courthouse by Thomas Phifer and Partners adopts a unique variation on a conventional steel frame structure enclosed by a glass curtain wall. The General Services Administration (GSA), which owns and manages federal properties, maintains strict federal standards for durability, adaptability, and security. These include earthquake resistance in this seismically active zone, and design to prevent progressive collapse including designing columns to support their own load plus the load from an adjacent column if it should fail.

The beams and columns at the perimeter of this steel frame are rigidly welded together so they cannot rotate. This moment frame resists the sideways or lateral forces from wind, earthquakes, or explosions. The perimeter moment frame stabilizes the whole structure and eliminates the need for typical structural cores inside the building. The interior columns only carry the vertical gravity forces, and have relatively small cross-sectional area of steel.

The outside of the building is clad in curtain wall, consisting of glass panels supported by aluminum frames called mullions. The façade hangs from the steel frame, expressing an image of transparent justice while allowing quality daylight into the interior. All-glass buildings present performance challenges: glass is a poor insulator from heat and cold, large windows admit too much solar heat, and high light levels cause glare, the contrast between light and dark. The US Courthouse addresses these concerns by using high-performance insulating glass; wrapping the façade with aluminum fins configured to block unwanted solar gains on each façade; and by painting the glass with a system of ceramic dots or frits to reduce contrast and glare.

Steel and aluminum have high embodied carbon: mostly because of the energy required to extract and refine raw materials. However, these metals offer high strength for their weight so relatively little material is needed. Unlike most composites, steel and aluminum are readily recycled; so designing for long life, adaptability, and end-of-life recycling can justify the high embodied carbon.

The US Courthouse anticipates future needs for more courtrooms by designing office floors to have floor-to-ceiling heights like the courtrooms. The concrete foundation of the elevated site plinth was built strong enough to support a future building where those offices would move when new courtrooms are needed. By avoiding functional obsolescence, providing extra structural capacity, and with memorable form and space, the US Courthouse offers a durable civic building.

MASONRY

Haus 2226, Lustenau, Austria, by Baumschlager Eberle Architekten

Haus 2226 combines architecture’s ancient tradition of massive construction and careful proportions with contemporary sensors and controls to eliminate heating and cooling equipment. “2226” refers to the range of comfortable temperatures this 6-story mixed-use building maintains year round without heat or air conditioning: between 22 and 26 degrees Celsius (71.6 and 78.8 degrees Fahrenheit).

The exterior walls of Haus 2226 consists of two vertical layers, or wythes, of Porotherm, a terracotta block engineered by Wienerberger AG for both structural and thermal performance. The outer wythe has more openings or voids inside to trap air and resist heat flow, so no other insulation is required. The inner wythe has more solid material, making it strong enough to provide the vertical structure, and to store heat as thermal mass. Together the solid masonry wall is 760 mm, or about 30 inches, thick.

The windows are arranged in a uniform pattern around the building to provide an even distribution of daylight. The solid walls between the windows allow interior partitions to divide the space for future uses. A digitally controlled vent panel beside each window automatically opens and closes in response to interior temperature and carbon dioxide levels, or people can voluntarily open or close the vents. As a result, users in this building only breathe fresh air.

The thick exterior wall shades the deeply inset windows, and the tall narrow shapes admit light deep into the interior. The white lime plaster coating the walls and ceiling reflect diffused daylight throughout the interior and absorb or release moisture depending on the relative humidity. These massive masonry walls balance temperature, humidity, and natural light throughout the day and over the seasons. The architects argue that the Haus 2226 demonstrates a simple, robust approach to make architecture “comfortable, energy-saving, and healthy.”

TIMBER

Wood Innovation and Design Centre, Prince George, BC, by Michael Green Architecture