Building Materials Outline Materials for Sustainable Sites Materials or Products that Minimize Environmental Impacts Smart Materials Extending the Lifetime of Materials (mtls.optimization)

Materials for Sustainable Sites Use No New Materials, Don’t Rebuild Reuse Existing Structures in Place Reduce Material Use Use Durable Materials

Reclaim and Reuse Materials or Products in Whole Form Use Reclaimed Materials from Other Sources Reprocess Existing Structures and Materials for Use On-site (downcycle)

Use Reprocessed Materials from Other Sites Specify Materials and Products with Reuse Potential and Design for Disassembly (DfD) Specify Recycled-content Materials and Products Use Materials and Products with Recycling Potential

Reclaim and Reuse Materials or Products in Whole Form Use Reclaimed Materials from Other Sources Reprocess Existing Structures and Materials for Use On-site

MATERIALS OR PRODUCTS THAT MINIMIZE ENVIRONMENTAL IMPACTS Use Sustainably Harvested or Mined Materials Use Certified Wood Use Minimally Processed Materials Specify Low Embodied Energy Materials

Use Local Materials Specify Low-polluting Materials Specify Low-water Use and Low– water-polluting Materials Specify Materials Produced with Energy from Renewable Sources

MATERIALS OR PRODUCTS THAT POSE NO OR LOW HUMAN HEALTH RISKS Low-emitting Materials and Products Specify Materials or Products That Avoid Toxic Chemicals or By- products

MATERIALS OR PRODUCTS THAT ASSIST WITH SUSTAINABLE SITE DESIGN STRATEGIES Products That Promote a Site’s Hydrologic Health Materials and Products That Sequester Carbon Products That Reduce the Urban Heat Island Effect Products That Reduce Energy Consumption of Site Operation Products That Reduce Water Consumption of Site Operation

Two types of Smart materials Type 1  property-changing Chromics or ‘color-changing’ smart materials  Type 2 – a material or device that transforms energy from one form to another to effect a desired final state.

CHROMICS OR ‘COLOR-CHANGING’ SMART MATERIALS Fundamental characteristics of chromics A class of smart materials that are invariably fascinating to any designer is the so-called ‘color-changing’ material group which includes the following: * Photochromics – materials that change color when exposed to light * Thermochromics – materials that change color due to temperature changes. * Mechanochromics – materials that change color due to imposed stresses and/or deformations. * Chemochromics – materials that change color when exposed to specific chemical environments. * Electrochromics – materials that change color when a voltage is applied. Related technologies include liquid crystals and suspended particle devices that change color or transparencies when electrically activated.

Dichroic light field from James Carpenter Design Associates. To animate a blank, brick fac¸ade, a field of 216 dichroic fins was attached perpendicularly to a large plane of semi- Reflective glass. Schematic representation of Mike Davies’

‘Hyposurface’ installation combines position sensors with conventional actuators to create a responsive surface. Images courtesy of Marc Goulthorpe and DeCOI Architects

Phosphorescent material translucent covering voltage source to Electroluminescent wire

A ‘cloth’ made by weaving fiber-optic strands that are lighted by light-emitting diodes (LEDs). (Yokiko Koide

Aerogel has a density only three times that of air, but it can support significant weights and is a superb insulator. Aerogels were discovered in 1931 but were not explored until the 1970s. (NASA)

The ‘heat’ chair that usesthermochromic paint to provide a marker of where and when the body rested on the surface. (Courtesy of Juergen Mayer H)

Fiber-optics, dichroic glasses and LEDs were used by James Carpenter Design Associates in this lobby installation for Bear Stearns in New York. The green zone is produced with fiber-optics and dichroic glass, it serves as a soft contrast to the moving blue LED information screens. (James Carpenter)

Type 2 – smart materials  a material or device that transforms energy from one form to another to effect a desired final state.

Aegis Hyposurface by deCOi Architects. Each moving element of the panel was driven by pneumatic actuators

Lighting simulation of interior office space using Radiance software. The contours illustrate the large variability that occurs in typical spaces. Simulation courtesy of John An.

SMART MATERIALS AND NEW TECHNOLOGIES An important category is the environment of the application:  can the material function in a corrosive atmosphere, can it withstand being submerged in sea water?

 classifications might include cost, availability, or recyclability as categories of equal importance to the more basic descriptive ones such as state and composition.  the final objective in all engineering applications is the optimization of a material