With industry advancements in airtight construction practices, our focus must turn directly to the profound impacts that interior materials and finishes can have on the health and comfort of the people living in the homes we build and remodel. Material selection is already complex for green building projects, so vetting products for sustainable interiors requires filtering them to protect the health and safety of the indoor air quality (IAQ) as well as to provide resource effectiveness. Th e good news is that having a high-performing, healthy interior doesn’t require sacrificing comfort, aesthetics, or well-being. In fact, sustainable design enhances these qualities, and with a wide range of product knowledge, credible guidance, and extensive research, interior designers can help you achieve your sustainability goals.
Here’s our guide to product selection for sustainable interiors. From the start, it is imperative that the project have clearly defined goals and objectives. Involve the interior designer early, giving us equal opportunity to contribute to the building as a whole. The process begins with researching interior product attributes beyond the primary design mission by digging deeper into understanding the composition and chemical makeup of every product. By analyzing all aspects of a building’s interior we identify and implement ways to save energy and water, to reduce CO2 emissions and waste, to improve IAQ, to be responsive to environmental impacts, and to be stewards of our resources.
Interior building materials, furniture, and equipment contain potential contaminants and particulate substances that can compromise the interior environment, some throughout their full life cycle. In an ideal world the target is a toxin-free interior environment that is resource effective, but we aren’t quite there yet. Specify materials that meet the following goals:
• least toxic, low- or zero-VOC/SVOC;
• emit little or no odor;
• not predisposed to moisture damage, fostering mold growth;
• easy to clean and maintain;
• adopt consensus standards and certifications; and
• products that take on the material criteria outlined below.
Based on material goals, utilize product consensus standards that have been developed by government agencies, environmental certification services, or trade organizations that address health and toxicity issues. Standards provide the industry with guidelines and criteria to judge a product on single or multiple attributes. Certifications indicate whether a product has met a specific standard like American National Standards Institute (ANSI) and International Organization for Standardization (ISO). For certification levels, we prefer products that obtain an independent third-party certification. This is followed by a second party that typically comes from associated trade organizations.
Manufacturers recognize that designers work closely with consumers promoting product attributes, standards, and certifications. By engaging with the design/build community, they are getting the message that health and environmental issues need to be balanced and recognizing the importance to the building industry and consumers. The range of healthy and sustainable product offerings is on the rise, plus manufacturers are investing in educating their sales staff through credentialed organizations. While there are trade-offs, we seek out transparent and accurate claims of sustainability and toxicity.
Indoor Air Quality
With the industry assembling airtight buildings there is nowhere for the accumulation of potentially hazardous chemicals and particulates to go unless we balance mechanical and natural ventilation systems, use advanced building science, manage moisture, and thoroughly evaluate material selections.
In addition to IAQ, interior finishes directly affect the performance of building assemblies. Understanding the vapor permeability of a product and the vapor profile of a building assembly is significant. Essentially we need to know which direction the building is drying—either to the inside or the outside—to support a high-performing assembly. Once we know the permeability ratings of all the assembly components and the direction of the moisture drive, we can support drying with our material selections.
Also, the moisture level of products entering the construction site is an essential step of the IAQ management plan. Ensure that humidity levels of wood products are appropriate for the climate and protect any on-site products with absorptive characteristics from potential moisture damage. Lastly, before applying finishes, substrates must be completely dry and ready to receive the finish product.
If done right, the interior materials will not contribute to the accumulation of unhealthy emissions, particulates, and mold, effectively reducing exposure risks. We take into consideration all the potential sources of indoor air pollution from building materials and products, including carpet and padding, flooring, paints and coatings, adhesives and sealants, wall coverings, appliances and equipment, cabinetry and wood products, insulation, and the furnishings, textiles, and cleaning products brought in by the occupants.
Utilizing specification criteria, we assess materials and installation methods incorporating this information into our design and construction documents. By using a comparative process, this allows us to weigh and balance product attributes and their impacts alongside project considerations taking into account the following decisive factors.
To achieve IAQ objectives we research materials in advance, review manufacturers’ certifications plus Material Safety Data Sheets (MSDSs), especially when standards or other references do not exist, and require submittals of the MSDS by the contractor. Review and approve requests for product substitutions to ensure that IAQ criteria defined in the specifications have not been compromised. Require MSDSs and other certifications for any product substitutions affecting critical items.
For the majority of product types, our go-to resources for healthy IAQ are Greenguard Children & Schools; Scientific Certification Systems (SCS) Indoor Advantage Gold; and the Carpet and Rug Institute (CRI) Green Label Plus. They are based on the stringent California Section 01350 standard, which adopts higher levels of emission specifications than others. CRI Green Label Plus is a second-party certification that requires third-party testing for VOCs and individual chemical concentrations based on California 01350 offering a solid standard. These organizations have excellent, searchable product databases.
Also, specific to composite wood products, seek manufacturers attaining the California Air Resources Board (CARB) Airborne Toxic Control Measures for a reduction in formaldehyde emissions. CARB 1 is quickly becoming the industry standard, and CARB 2 may become the new national regulation.
For the highest level of IAQ, we make a serious effort to avoid the following materials or chemicals from the Living Building Challenge’s (LBC) Red List: asbestos, cadmium, chlorinated polyethylene and chlorosulfonated polyethylene, chlorofluorocarbons, chloroprene (neoprene), formaldehyde (added) and a known carcinogen, halogenated flame retardants, hydrochlorofluorocarbons, lead (added), mercury, petrochemical fertilizers and pesticides, phthalates, polyvinyl chloride (PVC), and wood treatments containing creosote, arsenic, or pentachlorophenol. LBC has noted that there are exceptions for numerous Red List items due to current limitations in the materials economy. Refer to the LBC Community Dialogue for complete and up-to-date listings.