Over the last few years continuing pressure has been placed on the construction industry to ensure that our community responds to a global commitment to design buildings that promote environmental and economic sustainability. In order for the design professional to address and act on these concerns, they must evaluate a number of divergent building products. Comparative data can be analyzed and ultimately, design professionals must balance their choices based on the technical performance and aesthetic needs of their project, its users and the client.
"Green building" is a loosely defined collection of land-use, building design, and construction strategies that reduces environmental impacts. When considering alternatives for material selection, all aspects of environmental impact throughout the entire product life cycle should be considered, in other words, from cradle to grave. Thorough life cycle assessment includes: raw material or resource extraction; production processing and packaging; transportation of raw and finished materials; the energy to install, use and maintain the product; health impacts on the installer and the user; and finally disposal at the end of the products use, with consideration on whether the waste material is recyclable, salvageable, biodegradable or conversely, a burden on our landfills.
Many directories and guides have been issued in an attempt to classify green building materials. The Holy Grail of the green building movement would be a database in which the life-cycle environmental impacts of different materials were fully quantified and the impacts weighted so that a design professional could easily see which material was better from an environmental standpoint. Though efforts have been made, we are not even close to realizing that goal. Very often, we are comparing apples to oranges. One must address several very diverse issues. Often we are comparing the resource-extraction impacts of one product with the manufacturing impacts of another, and the indoor-air-quality impacts of a third. This is not an exact science and as further data and studies are done, more accurate analyses will be possible. However, environmental experts agree that the relative "greenness" of products is secondary to establishing integrated green design strategies. It is why programs such as LEED (Leadership in Energy & Environmental Design) evaluate buildings (systems) and not individual products.
Yet, retailers who sell green products and support sustainability often single out one element of green design - material with recycled content and hold this up as their flag. Recycled content may be the easiest feature to identify and quantify but relying on this measurement tool only may exclude materials that are more energy efficient, healthful and at times the most environmentally preferable products. Using this single identifier could potentially lead to promoting an eco-responsible paint that requires multiple coats, which, may defeat any environmental benefits it seemingly offers. "Green Retailers" also report that life-cycle assessment (LCA) tools are rarely, if ever used in their product review process. Without considering the LCA of a product it is difficult to know if they are as environmentally friendly as they appear. One philosophy in building design that appears to take the longest view as well as capture the essence of sustainability is to build for longevity. There can be nothing more environmentally friendly than architecture that is built for centuries rather than decades. Selecting quality products that are durable and will not need to be replaced within the life of the structure substantially reduces resource extraction, manufacturing, transportation, installation and demolition energy requirements. When materials also offer: reduced maintenance; improved Indoor Air Quality; low toxicological impact; and are inert, low burdening waste at the end of their life, we should be considering these products along with materials being promoted solely due to their re-cycled content.
Unfortunately, when consumers search for lists of green floor and wall products, ceramic tile is often little more than a footnote. Although durability is cited on the plus side, the high embodied energy required to produce and transport tile has become the sole factor in limiting the list of suggested choices to ceramics that include recycled content. Factors not considered are the positive attributes ALL ceramic tiles possess regarding installer and occupant health: low emissions in use, installation and production and the low contribution of chemical wastes to our ecosystem due to the ease of maintenance. There is a substantial case for increased use of ceramic tile and stone, wall and floor applications when the intention is to build a healthy, environmentally conscious, sustainable building.
What makes a material green? Products made from environmentally attractive materials.
Salvaged products: Whenever we can reuse a product instead of producing a new one from raw materials, we save on resource use and energy. Salvaged limestone, marble, granite and terra cotta tiles are prized materials throughout the world. The historical, cultural and architectural importance of each of these reclamations adds to their value as a lifelong investment. Taking a broader view, all ceramic tile and stone installations, are considered to have a useable life of well beyond 40 years. Alternate flooring choices will be replaced 4, 6 or 8 times in that same period. Therefore, the embodied energy required to extract, produce and transport the original tile must be compared to the embodied energy of alternate products multiplied by the frequency of replacement or up to eight times the initial energy expenditure.
Reuse: Ceramic tile is the hero of disasters and can be repaired if damaged by water, fire or mechanical impact without replacing or disposing of the entire flooring material. Setting aside a reasonable quantity of reserve stock, from the original production lot, can also double the life of the floor or wall as it enables replacement of any naturally worn or trafficked areas. This feature greatly reduces the need for replacement material and resources.
Many ceramic tile and stone installations can be left intact if new flooring is desired. Tile-over-tile installations are common today with advancements in setting material technology.
Products made with post-consumer or post-industrial recycled content: Tile manufactures employ sophisticated dust collection systems and reclamation processes to reuse all unfired raw waste generated by production. Fired waste product is utilized in new glaze technology with the balance used in roadbeds and construction fill requirements. In addition the major ceramic tile manufacturing countries have been consistently improving manufacturing techniques. The manufacturing process recycles 100 percent of retained production water resulting in a drastic reduction in water consumption. In the past twenty years the industry has tripled its production yet managed to reduce gaseous emissions by 75 percent of original 1970s consumption levels required to produce one third of the product.
Use of rapidly renewable or plentiful natural raw materials: Ceramic tile is made of 100 percent natural and plentiful raw materials. Tile is generally a mixture of clay, sand and carbonate or feldspars. These materials are combined with water and fired at high temperatures rendering the material hard, compact and impermeable. At life's end ceramic tile is a low volume, environmentally inert and stable material with low disposal costs.
Green because of what isn't there: Products are included in this category because they are alternatives to conventional products made from chemicals considered problematic. Ceramic tile and natural stone are inert and contain no Volatile Organic Compounds (VOCs) and are therefore appropriate substitutes for many other finishes. Cement based setting materials also perform with minimal off gassing and do not emit potentially harmful VOCs into the interior environment. Ceramic tile and stone are benign relative to many conventional products they can replace. Alternates should be found to replace products or substances that are ozone depleting, made from PVC and polycarbonate, preservative-treated wood or any other components considered hazardous.
Products that reduce the impacts of renovation: Ceramic tile as previously noted does not have to be removed and areas of tile can be extended during renovation when reconfiguration of a space is required. Because ceramic tile is unaffected by Ultra Violet light it retains its color permanence and new tiled areas can be blended with original tiling without the appearance of patching. Therefore, reconfiguration of both home and workspace is not compromised by fading or deterioration due to protracted exposure to the sun.
Products that reduce environmental impacts of building operation: Ceramic tile and natural stone effectively retain both heat and the cooling effect of air conditioning. This feature can reduce the energy consumption required for a building. The inclusion of today's advanced radiant floor warming systems, contribute to further reductions in energy costs as rooms can be heated at a lower temperature. With radiant heating under-foot the warmth goes straight to one's body, so you can feel warmer at a lower temperature. Forced air systems and baseboard heaters need to heat up the entire room before one begins to feel warm. Radiant heat has been found to be the most comfortable, energy efficient form of heating. NuHeat, one manufacturer of electric radiant heating pads for use under ceramic tile has earned the Energy star rating set by the EPA and the US Department of Energy for their MatComfort 7 day thermostat. The company claims that families can save approximately one third on their energy bill with similar savings of greenhouse gases without sacrificing feature, style or comfort.
Products with exceptional durability or low maintenance requirements: The exceptional durability of ceramic tile is directly related to the impervious glazed surface, which, requires low-cost maintenance and no chemical or protective finishes. Warm water and neutral cleaners are the only cleaning products required.
Products that contribute to a healthy indoor environment: This strategy includes products that do not release significant pollutants into the building. Ceramic tile and stone are neither an original nor secondary source of VOC or other indoor pollutants. This means that during their initial installation and throughout their useful life, they do not contribute to poor air quality. Ceramic tile will not give off odors or absorb odors from other contaminants. Therefore, smoke, paint fumes or other odors do not linger and are not re-circulated. There are generally no fibers, gases or toxic by-products when installing or living with ceramic tile. Tile is chemically inert and inhibits the growth of mold, mildew, fungus and other viruses.
As with any comparative analysis it must be assumed that competing material alternatives all meet minimum technical performance requirements. However, there may be significant differences in performance, such as acoustical, fire, or aesthetics that may conflict with environmental and economic considerations. The features noted above highlight some of the significant contributions ceramic tile and stone can achieve when used in an overall design strategy. It should also be noted that the complete building design context must be developed and interactions among building elements analyzed. The useful life of one building element e.g. floor coverings, which influences both its environmental and economic performance attributes, may depend on the selection of related building elements such as subflooring. There is no substitute for good building design and the implementation of a systematic design strategy.