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CHEMISTRY AND THE BUILDING PROCESS FOR ARCHITECTS

Chemistry is an important, but often not fully understood, component of the modern building industry. Architects, designers, builders, and occupants may not recognize the myriad benefits that chemistry provides to the built environment. Although each of us comes into regular contact with products made possible by chemistry, few understand materials science, building science, and chemical engineering, or how these fields help provide a safer, healthier, more comfortable living environment.

CHEMISTRY AND OUR MODERN WORLD

Everything consists of chemicals. There are no “chemical-free” products—chemistry makes up

all things. Everything in the known universe is a special mixture of the 118 elements found on the periodic table. The science of mixing these ingredients is called “materials science,” and when it comes to improving the health and welfare, comfort, security, and safety of people and our planet, there are few disciplines more critical.

Materials science is an interdisciplinary field that deals with the discovery, design, and development of new and innovative materials. It is the characterization of the physical and chemical properties of materials. Materials science is essentially the study of “stuff”—and how stuff is put together. Through the study of

chemistry and materials science, we can better understand and improve a material's properties and performance.

Chemistry and materials scientists not only help create the things we use every day, they also improve the world around us. To better understand how materials science impacts our lives, consider some of the benefits provided by innovations in chemistry:

• In health care, chemistry contributes to advances in life-saving medical devices and equipment, as well as the pharmaceuticals and vaccines that play a key role in keeping us healthy. Through testing and study of different chemical compounds, doctors

By Andrew Hunt

Presented by:

LEARNING OBJECTIVES

At the end of this program, participants will be able to:

1. Understand how chemistry enhances performance in the building industry.

2. Explain the concept of risk verses hazard when considering the use of chemistry-enhanced building products.

3. Understand regulatory and testing requirements for chemicals.

4. Discuss the future of chemistry in the building industry.

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CREDIT: 1 LU/HSW

COURSE NUMBER: ARdec2015.2

Use the learning objectives above to focus your study as you read this article. To earn credit and obtain a certificate of completion, visit http://go.hw.net/AR1215Course2 and complete the quiz for free as you read this article. If you are new to Hanley Wood University, create a free learner account; returning users log in as usual.

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and researchers gain an understanding of how certain medicines affect human health, as well as the side effects, positive and negative reactions, and long-term implications of medicines and treatments. Commonplace medical procedures, such as open-heart surgery and cancer treatments, are only possible because of the efforts of materials scientists to bring new and better products to market.

• One of the most dramatic changes in recent history has been the rapid and expansive adaptation of communication devices. Today, most Americans can easily access information from the palm of their hands—news and current events, weather, traffic, and entertainment updates are available in real time, as are missives from friends and family. Our planet is connected electronically thanks to portable hand-held devices with digital displays and battery-powered components made possible by chemistry. Materials scientists developed the innovations that make our cell phones, tablets and laptop computers lighter, more durable, and able to send and receive information effectively.

• Innovations in materials science also enable cutting-edge advancements in transportation. Modern, lightweight plastics and composites already make up 50 percent of the volume of today’s automobiles, which makes cars lighter and more fuel efficient. Electric cars with rare-earth metal batteries and cars with hybrid engines powered by electric batteries made possible by chemistry are becoming more common.

In today’s built environment, there is strong demand for materials that are high-performing, cost-efficient with a lower environmental impact, that are easy to install and maintain, and that add to the aesthetics and design creativity that architects demand. Below are some examples of how the products of chemistry enable these demands to be met:

Enhanced Product Performance

Today, builders, designers and architects demand high-performing, technically sophisticated building products and materials that also are easy to install and maintain and that will retain both attractiveness and durability over their lifespan. For example, in roofing, plastics and coatings enable the huge, yet lightweight, domes that cover sports

stadiums. New, dramatic architectural features such as accented skylights that won’t crack or get brittle are made with lightweight, durable clear plastics. Skylights with built-in nano-gels also have insulating properties to enhance energy efficiency.

In windows and doors, color and design options increase. New chemistry innovations include “smart” coatings that can change colors based on the angle at which they are viewed. Some of these same smart coatings also have pigments engineered to reflect the infra-red heating rays and provide cool metal roof coatings or shingles that are up to 40 degrees F cooler than those without cool coatings. These features can add interesting aesthetics to building design, changing the look from the daytime to the evening.

Chemical innovations in insulation can strengthen structures, providing protection against severe weather impacts. Insulation also can minimize and discourage mold growth and reduce dust and allergens, thus improving indoor air quality. The energy-saving benefits of insulation products are described below.

Energy and Resource Conservation

The products of chemistry improve energy efficiency in our offices, homes, schools and factories. For example, plastic products used in roofing, insulation, exterior claddings, and windows can save up to 467.2 trillion BTUs of energy per year, enough to power 4.6 million homes annually. Insulation materials made possible by chemistry help save more than 200

times the energy needed to make them.

At the same time, chemical products also enable new technologies to generate and store energy, including photovoltaic solar panels that rely on silicone-based chemistry, and wind power turbine blades made using plastics and chemical additives that help deliver renewable energy to our nation’s power grid.

Materials science has made new, innovative functional uses for materials in the buildings sector that might have otherwise go to waste. For instance, one innovation in building has been the adoption of manufactured wood products. Structural composite lumber, parallel strand lumber, laminated lumber, and oriented strand lumber are created by layering dried wood strands or flakes with a moisture-resistant chemical adhesive. In rafters, beams and floor joists, composite wood products often outperform conventional lumber. Structural wood products provide more accurate and architecturally sound building materials, and they also make use of materials that might otherwise be discarded.

Affordable and Cost-Effective

Building owners and occupants want high-performing products that are also cost effective. Expanded material choices made possible by chemistry provide consumers with a wider selection of affordable, cost-effective products. For example, new chemistry-based materials can replicate the appearance of natural products like wood or stone.

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addition, specifiers can now ‘tune’ the window surfaces to reflect differently on different sides of the building, based on orientation to the sun. West- and east-facing windows can reflect more heat and energy and UV light (to avoid the bleaching effect of sun on interior furniture and fabrics), and north- and south-facing windows can let in more visible light and heat if needed in winter.

Polymer cladding over wood window frames can protect the wood from degradation caused by moisture, salt, sun, mold, and bugs. Additives to caulks and sealants used to reduce air and water leakage at the boundary between the window frame and the rough opening keep them pliable and in place for many years.

Air sealants

Air leakage can have debilitating consequences for buildings. In the summer, leaks can draw warm, humid air from the outside to inside, and in the winter, the same leaks can push warm air from inside the building into cold envelope cavities. Once inside the wall, warm, moist air condenses on contact with cooler surfaces, resulting in excess moisture that can lead to mold, rot, and even structural damage. This is in addition to increased heating and cooling costs, along with wear and tear on HVAC equipment that, all together, can create a host of problems for occupants, from high energy costs to indoor air quality issues due to mold and rot.

Windows

Single-pane glass windows do little to reduce the amount of energy that passes between the outside environment and inside of the home. But framing and glazing options have made major advancements, thanks to a better understanding of how air moves from the outside in and inside out through windows. Chemistry has helped minimize air movement in two important ways: 1) The glazing has expanded to multi-pane sealed units (double or triple instead of single), filled with krypton or argon inert gases in between each layer, and 2) Vinyl window frames feature chambered extruded designs to trap air and minimize its movement through the frame, making windows framed with vinyl extrusions very energy efficient.

Other improvements include low-e coatings applied directly to the glass surfaces and the films suspended between the interior and exterior glazing layers. While there are many different types of low-e coatings, most are microscopically thin, virtually invisible, comprised of metal or metallic oxide. Uncoated glass has an emissivity of 0.84, and some higher performing low-e coatings can reduce emissivity to 0.02.

Lower emissivity windows provide increased comfort and energy efficiency. Reflective or mirrored coatings applied to windows reduce transmission of solar radiation by blocking light. While they improve the solar heat gain coefficient (SGHC) rating, they also greatly reduce the visible transmittance (VT). Reflective coatings usually consist of thin, metallic layers, and come in a variety of colors including silver, gold, and bronze. Because of the reduced solar heat gain, these coatings are more common in hot climates to control solar heat gain. In

In addition, due to increased durability, the products of chemistry can have lower maintenance costs, enhancing their value over the long term. For example, cleaning today’s high performing floor or carpet treated with stain-resistant chemicals can be easier as spills can be wiped up with less chance of staining. Enhanced durability also can make building components more resilient and able to withstand extreme weather events like hurricanes or catastrophes such as fires and floods. As well, the ever-increasing need to keep costs down via low maintenance in build-outs relies on developments in materials science. The ability of a material to withstand a salt-water environment without rotting or rusting is one good example. The better a structure is designed, specified, and built, the longer it lasts.

ENHANCING BUILDING PRODUCTS WITH CHEMISTRY

In the commercial building environment, chemicals enhance performance in a range of products and applications, from flooring, furnishings, and lighting, to insulation and heating and cooling systems, to adhesives, epoxy linings, paints and coatings and sealants. Following are a few examples of how chemistry can enhance a variety of building products:

Chemicals are everywhere in the built environment, including the following popular building materials:

• Polyurethane: Used in spray foam insulation, roofing

• Extruded Polystyrene: Used in wall insulation panels

• Epoxies: Used in floor installations, countertops, and anywhere adhesion is important

• Composite Wood Products: Used in kitchen cabinets, outdoor deck tiles, fence panels

• PVC/CPVC: Used in siding, pipes, wire/cables, fencing/decking/railing, windows

• Polypropylene: Also used in siding

• Nylons: Used in carpeting

• Elastomers: Used in roof coatings, also caulks and sealants

• Polycarbonate: Used as glazing in skylight windows

• Acrylates: Used in caulks and sealants

• Acrylics: Used in paint

• Polyester: Used in bathroom countertops, tubs, and sinks; “artificial stone”

• Acrylonitrile Butadiene Styrene (ABS): Used in tub and shower surrounds, pipe/fittings, plumbing fixtures

• Polyethylene: Used in plastic pipes and fittings

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Through experimenting and testing a wide range of chemicals and approaches, chemists and materials scientists have developed sealants and low-pressure nonexpanding foam to effectively control and manage the differences in air pressure between the inside and outside of a building. A sealant can be used to seal gaps smaller than ½-inch wide and in irregular gaps. When applied with care, modern and improved sealants can create a tight seal around the shims used to install window and door units.

For larger gaps, low-pressure foam can be used to quickly and efficiently seal a gap between wall framing and windows or door units. Polyurethane-based insulating foam sealant can fill, seal and insulate small gaps up to 1 inch wide. It is important to use low-pressure foam because ordinary expanding foam can swell with enough force to distort the jambs and cause problems operating windows and doors.

Caulking and sealing joints and penetrations on the exterior cladding of a building are critical to help keep water from entering a building. Siding must be properly sealed in order to protect the building from water damage and the rot, mold, and poor indoor air quality that can result. The sealants and caulks made from foam stay flexible over a long lifespan so they don’t crack and shrink with age, oxidation and UV radiation from the sun. Also, additives allow these sealants and caulks to bond properly in cold weather, allowing for the construction cycle to be extended and maintenance to be done in winter.

Piping

Leaky pipes can cause a lot of damage quickly and quietly. Tough, flexible plastic piping manufactured using a variety of chemicals have a significantly greater life expectancy than metal counterparts and are less likely to corrode and leak. Polyvinyl chloride (PVC) piping is the most widely used plastic piping material. Other materials used in the manufacture of plastic piping include chlorinated polyvinyl chloride (CPVC), polyethylene (PE), cross-linked polyethylene (PEX) and acrylonitrile-butadiene-styrene (ABS).

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QUIZ

1. Which science looks to improve products by experimenting with elements from the periodic table?

a. Elemental Science b. Materials Science

c. Enhanced Science d. Mixology Science

2. How do advancements in materials science positively affect the building and construction field?

a. Reduced energy consumption b. Resource conservation

c. Safety d. All of the above

3. In windows, what is emissivity?

a. Windows that are placed at a higher altitude b. A product that missed its safety check at the manufacturing site

c. Off gassing from manufacturing d. The ability of a window to radiate energy

4. What are argon and krypton used for in windows?

a. The void space between multi-paned windows b. Modern windows are coated with these is often filled with these gasses, reducing heat transfer gasses to reflect sun rays

c. Traditional windows used these gasses d. They act as a sealant between the window frame to reduce costs and the casing

5. What chemical advancement has been made to air seal larger gaps in the home up to 1 inch?

a. Wider shims b. Heavy duty weather stripping

c. Low pressure non expanding foam d. Argon filled caulking

6. True or False: VOC’s should never be used in the building process.

7. How do scientists evaluate risks and hazards?

a. Elemental Science Handbook b. Potential exposure

c. Food based studies d. Building industry experts

8. What is the primary agency responsible for regulating chemicals in commerce?

a. Chemical Commission Council b. Organic Compound Agency

c. Scientists Association d. Environmental Protection Agency

9. What is the main reason that chemicals are added to building materials?

a. Improved odor b. Improved performance

c. Overseas manufacturing d. Improve production times

SPONSOR INFORMATION

The American Chemistry Council represents the leading companies engaged in the business of chemistry. ACC members apply the science of chemistry to make innovative products and services that make people's lives better, healthier and safer. ACC is committed to improved environmental, health and safety performance through Responsible Care®, common sense advocacy designed to address major public policy issues, and health and environmental research and product testing.

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When in doubt, ask a scientist. The terms “hazard” and “risk” seem similar, but to a scientist they are actually very different. In chemistry, the terms have very specific meanings:

• Hazard refers to the inherent properties of a chemical substance that make it capable of causing harm to a person or the environment.

• Exposure describes both the amount of, and the frequency with which, a chemical substance comes into contact with a person, group of people or the environment.

• Risk is the possibility of a harm arising from a particular exposure to a chemical substance, under specific conditions.

So, as with a mathematical equation, scientists look at risk as the inherent hazard of a material, relative to the level of exposure to that material. For example, a highly hazardous material like cyanide is of little risk to people as long as there is limited exposure. The type of exposure is also important to understand. Many chemicals and materials in daily life are relatively harmless unless we are exposed in specific ways.

A classic example of relative risk, hazard, and exposure is water. Water in the bath and shower on the outside of our body poses no risk. Water consumed by drinking poses no risk and is necessary for life. But a quarter cup of water inhaled into our lungs can be fatal. So the risk associated with water changes, depending on the amount and type of exposure.

So what does risk mean in relation to the products we use every day? When it comes to chemicals, the concept of reasonable risk can be overshadowed by blaring headlines and myths. For architects and builders, this can be problematic—when designing and constructing a building, they want to select and use products and materials that are durable, high-quality and energy efficient, that will also provide comfort and be aesthetically pleasing. For example, spray foam insulation made from polyurethane is an effective air and moisture vapor barrier, which can enhance energy efficiency and limit mold growth.

However, some products used in building and construction may contain chemicals that have raised the public’s concern. The key to managing these concerns is in understanding the differences between risk and exposure.

standards, and they can increase the efficiency of mechanical systems, which could allow for additional savings in reduced HVAC requirements. Open- and closed-cell spray foam can act as a moisture vapor barrier. In addition, sealing gaps and air leaks can prevent humidity and condensation within a building. By controlling moisture, spray foam can limit one of the key variables that can lead to mold growth.

In addition, well insulated buildings reduce sound transfer between walls and floors and also help to strengthen the building skeleton against severe weather and other impacts.

Flooring

The products of chemistry enable a range of possibility for creative, attractive and durable flooring options. In high-traffic corridors, vinyl tile is a long-lasting, easy-to-clean flooring option. Polyurethane-based topcoats can enhance scratch resistance to extend floor life even longer. In addition, antimicrobial surfaces in vinyl flooring help keep germs in check in public areas.

Carpeting made from nylon, or other fibers like polyester or polyolefins, are stain- and moisture-resistant. Soft polyurethane padding underneath carpets makes them more comfortable, as cushioned surfaces are less painful on legs, feet and joints when standing for prolonged time periods. It also helps insulate against the cold and acts as a sound barrier in offices and other high-occupancy buildings. Carpet tiles also are a durable, attractive flooring option, and individual tiles can be replaced as needed and the material reused.

UNDERSTANDING RISK, HAZARD AND EXPOSURE

As stated at the outset of this article, everything around us—the entire human body and everything we eat and drink—is made up of chemicals. And chemicals that are characterized as “toxic” or “hazardous” are not limited to those manufactured in a laboratory; they occur naturally in the human body and the environment and are all around us.

Every day, we are exposed to materials, foods, products, and situations that carry an uncertain level of risk to our health and well-being. Chlorine and fluoride are in the water we drink, providing sanitation and health benefits, but too much of either of these chemicals is fatal. So, how much is “too much”?

Plastic piping is not degraded by underground water and soil, or by contaminants or acidity in waste or sewage passing through it. Plastic piping can be used in a variety of building applications, including water mains, hot and cold water distribution, drain, waste, and vent (DWV), sewer, gas distribution, irrigation, conduit, fire sprinkler and process piping.

All plastic piping materials have low thermal conductance properties, which help maintain more uniform temperatures than when transporting fluids in metal piping. The low thermal conductivity of the wall of plastic piping may greatly reduce or eliminate the need for pipe insulation to control sweating. Thermoplastic piping also is flexible and does not need to be joined with lead solder, enabling use of efficient installation techniques. The joints are sealed and more able to withstand vibration and less prone to cracks and leaks when buildings shift, settle, or sway in the wind.

Insulation

Energy-efficient insulation products help keep buildings temperate, reducing the costs of heating and cooling. Spray polyurethane foam (SPF) is a spray-applied plastic that can form a continuous insulation and air sealing barrier on walls, roofs, around corners, and on all contoured surfaces. It is made by mixing and reacting liquid components at the job site to create foam that insulates, seals gaps, and can form moisture and vapor barriers. SPF insulation can resist heat transfer, and it also can reduce unwanted air infiltration through cracks, seams, and joints.

Designing with spray foam allows an architect to use one product for many purposes: to achieve an air barrier, vapor barrier and provide effective insulation, for cost-effective building design and energy-efficient building performance. Effective air barriers are now an integral part of building codes and

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Other materials found inside a building, like some floorcoverings and furniture, have a higher degree of exposure to building occupants. But again, a full evaluation of the risk is required. Innovations in chemistry have enabled the development of new products which meet rigorous indoor air quality testing standards, that don’t “off-gas” or that primarily release VOCs upon installation and then mature or cure within the building envelope.

Following proper product installation guidelines can limit occupant exposure to VOCs. Most new construction and renovation projects now allow an appropriate time period for the space or entire building to “flush” prior to occupancy, allowing for any VOCs in these building products to be dissipated before the occupant even steps foot in the building.

Finally, proper building ventilation is an extremely important factor in improving and enhancing indoor air quality. Many of today’s modern buildings have effective ventilation systems that enable continuous flow of air inside the building. Plastic products like vinyl window frames can help the ventilation system work more effectively by helping to control the condition of the air entering and exiting the building.

Choosing the Right Product

Key to being an informed architect is recognizing that even when a chemical is present in a building material or product, it does not mean there is a risk. There is a process by which chemical ingredients used in materials and products can be assessed for safety, taking into account risk, hazard, and exposure. Scientific experts at government agencies use computerized evaluation procedures, data, and testing to establish safe exposure levels for chemicals in products. Companies that make consumer products are also responsible for the safety of the products they sell, and many do their own robust evaluations and safety testing.

All materials used in building and construction have different strengths and weakness, so when making material selections, architects and builders need to understand these trade-offs. One can only accurately evaluate a product by looking at all aspects of the product, rather than just focusing on one single attribute. Safety and environmental considerations, as well as energy efficiency, should be a part of building design and purchasing criteria. The process for establishing “sustainable” product and material criteria should include

VOCs may raise concerns about materials or products that contain these compounds. But this reaction is not always reasonable, due to what we know about risk, hazard and exposure. A rational approach to specifying and installing materials should be followed.

For example, insulation materials that contain flame retardants are installed within walls and unconditioned spaces. Occupant exposure to the insulation and its ingredients is minimal, because the flame retardants are intact in the product, and the insulation itself is not directly in contact with building occupants. From a practical standpoint, the potential benefits in fire prevention often exceed the perceived risk associated with these materials because when computing the hazard and exposure potential, risk to the occupant is low.

Likewise, products used on the roof or exterior of a building to help shed and manage moisture pose little concern to building occupants, because VOCs dissipate quickly in the open air, and both frequency and concentration of exposure is very low.

Understanding how to rationally recognize and address potential risk is critical if architects and builders hope to maximize the benefits of materials science.

Chemicals and Indoor Air Quality

According to the U.S. Environmental Protection Agency (EPA), Americans spend more than 90 percent of their time indoors. Indoor air quality refers to the air quality within and around buildings, especially as it relates to the health and comfort of building occupants. Indoor air quality can be compromised due to a lack of proper ventilation, coupled with gases, such as carbon monoxide, radon, volatile organic compounds (VOCs); and particulates and microbial contaminants such as mold and bacteria, present in the enclosed space.

The products in a building by their nature affect indoor air quality. For example, paints, varnishes, and waxes, as well as many flooring, sealing, and insulating materials and cleaning products all contain solvents, which are generally classified as VOCs. A quick Internet search on

PRODUCT LIFE CYCLE

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In addition, architects and builders can refer to a range of green building standards, codes, and certification systems when making materials selection decisions. When choosing a green building system, builders and architects should look for a system that is consensus-based, with a development process that is recognized as fair, inclusive, and transparent. Good standards are data-driven, include multiple attributes for evaluating products and materials, and are supported by science.

In some situations, the architect or builder may want to assess alternatives for products that contain a chemical of concern. Using an alternative might be an option to help mitigate risk, but the user should take care to learn exactly why one product is recommended over another. A substitute material that is considered less hazardous could have negative impacts—the substitute products might be less

consensus-based decision-making, the best available science, transparency and openness to all relevant stakeholders.

When choosing materials and products, an architect or builder may choose to undertake a “life cycle assessment,” or LCA, for the specific product or material. An LCA is a standardized tool or method for calculating the impact of different materials. It is used to systematically evaluate multiple potential environmental impacts of a product or process throughout its lifespan. An LCA can help identify opportunities to reduce potential impacts and minimize resource usage across a product’s current life cycle, as well as to evaluate proposals for change within a product’s life cycle. It also serves to identify tradeoffs in the form of inadvertently increasing certain environmental impacts when attempting to decrease other environmental impacts.

durable or have increased maintenance costs, or the product you are removing might need to be replaced with multiple other products.

The final decision about which products or materials to use for a specific project should take into account overall design goals, healthfulness, energy efficiency, and, of course, budget.

Regulating Chemicals Used in Products

The U.S. Environmental Protection Agency (EPA) is the primary federal agency responsible for regulating chemicals in commerce. More than a dozen federal laws govern the safe manufacture and use of chemicals in the United States. All new chemicals must be evaluated before commercial manufacture. EPA also has authority to request information on chemicals, as well as additional testing of chemicals as deemed necessary.

The EPA has been regulating chemicals since the agency was created in the 1970s. There have been more than 36,000 premanufacturer notices reviewed since 1979. Of those, the EPA has taken regulatory action on less than 10 percent, and 5 percent have been withdrawn and were not allowed to come to market. This is important to note because it shows how much work goes into ensuring chemicals are used safely in the product, and that the product is used safely in the building or construction industry.

EPA has a comprehensive review process for chemicals before they are introduced into the marketplace:

1) Chemical manufacturers submit PMNs (premanufacture notices) to EPA.

2) EPA conducts an initial review of a company’s PMN, including all health and environmental data and information provided.

3) EPA experts apply predictive models to develop a “profile” for the chemical, using sophisticated computer modeling to predict the chemicals properties, and create models based on structurally similar chemicals.

4) EPA analyzes the chemical’s properties, including health effects data, environmental effects data, physical properties and other data, and estimated potential impacts. If EPA has questions or needs additional data, it can and does request more information. Using this

EPA CHEMICAL REVIEW PROCESS

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provide a low cost way to increase the efficiency of older, existing windows costly without replacement.

• “Low emissivity” coatings and films that can be placed directly onto window glass allow architects to “tune” the glass or glazing, to select different products for various sides of the building’s exposure. This approach would allow selecting windows, for example, on the West side of a building that adjust solar heat gain and the North side of a building that allow for controlling the amount of heat that can escape.

• Other new window technologies include polymer sealants and caulks that hold the glass in place around the edges of the frame and firmly separate the two panes of glass from one another. This technology creates the window “spacers” so that inert gases can be infused between the panes, limiting the heat transfer between the two or even three panes of glass.

Chemicals and materials science are a vital and important part of the building and construction industry. From the first time fire was struck in pre-historic times, humans have been using chemistry to improve lives and make homes more functional, safe, and comfortable. As materials scientists continue to research and improve building products, architects and builders will benefit from these new innovations. ◾

insulated plumbing system that could provide instantaneous hot water regardless of the length of the run or distance to water heater.

In fact, ongoing materials science innovations are enabling still greater technologies and products to enhance building and construction. For example:

• New lighter, but strong, concrete additive mixtures substantially reduce the amount of cement needed in concrete, thus making concrete easier to transport without sacrificing strength. This tech-nology was used in the construction of the new World Trade Center Buildings in New York City, and in the Burj Khalifa hotel in Dubai, the tallest building in the world. Polystyrene beads are mixed into the concrete, lowering its weight and improving insulating properties. Chemistry also lowers the viscosity of the mix so it is thin enough to be pumped up to the very tall floors—over 100 levels—avoiding past costly, time-intensive practices that required concrete to be hauled up very tall buildings in buckets.

• A number of new performance films work by controlling the passage of solar energy into commercial buildings, as well as homes and cars. These films improve the performance of windows, providing endless aesthetic opportunities, while reducing the safety and security hazards associated with glass windows. Films

information, EPA identifies health and environmental hazard potential.

5) EPA analyzes exposure potential to humans and the environment.

6) Following this process, EPA has authority to reject or limit a new chemical’s use, or allow manufacture without restrictions.

EPA’s authority extends beyond the initial manufacturing of a chemical. Once approved, a chemical remains under the purview of EPA, which has authority to evaluate, require reporting, and demand additional testing.

This oversight of new chemicals and products may delay new products to market for years, driving up research and development costs for manufacturers and also preventing smaller innovations in materials science from reaching the market. However, this methodical, thoughtful process helps protect consumers, and the building and construction industry from liability in rushing to use materials or products that may not be safe.

CONCLUSION: THE FUTURE OF CHEMISTRY AND THE BUILDING INDUSTRY

As an architect concerned about the quality of the built environment, you may envision improved products or building materials that make the job of designing a well-built home easier. Imagine a building wrap material that could be installed flawlessly every time, prevent moisture intrusion, repel termites, work in any climate, and cost pennies per square foot. Or an

RESOURCES AND ADDITIONAL INFORMATIONU.S. Department of Energy, Energy Efficiency & Renewable Energy, Building Technologies Program: “Measure Guideline: Energy Efficient Window Performance and Selection,” http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/measure_guide_windows.pdf

U.S. Department of Energy: “Air Sealing Your Home,” http://energy.gov/energysaver/air-sealing-your-home

U.S. Department of Energy: “Window Types,” http://energy.gov/energysaver/articles/window-types

U.S. Environmental Protection Agency: “Lead Poisoning: A Historical Perspective,” http://www2.epa.gov/aboutepa/lead-poisoning-historical-perspective

U.S. National Library of Medicine: “Paths to Acceptance: The advancement of scientific knowledge is an uphill struggle against ‘accepted wisdom,’” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2373380/

Chemical Safety Facts: http://www.chemicalsafetyfacts.org

Green Building Solutions: http://www.greenbuildingsolutions.org