Where in home building do risk and doubt converge? In indoor air quality matters, that's where. For big builders, the dilemma about indoor air quality falls somewhere on the spectrum of what they must do to be in compliance with code, what they could do to be ethical, and what they'd be smart in doing to avoid future liability. Add in a hefty cost factor that plays havoc with internal rate of return models, and you've got a doozey of an issue. That is where indoor air quality is right now.

The American Society of Heating, Refrigeration and Air-Conditioning Engineers has published Standard 62.2-2004, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, which is, to date, the best practice on what builders can do to ensure indoor air quality safety. What's more, the Environmental Protection Agency cites poor indoor air quality as one of the top five environmental threats between energy-efficient building envelopes and indoor air pollution.

Certainly home builders “get” the engineering standards. Still, the lack of code requirements creates a business challenge for home builders, especially as public awareness of the negative effects of poor indoor air grows. Contributing to the controversy are high-visibility litigations associated with the growth of indoor mold and emissions from carpet. Minus the teeth of code requirements, will builders adopt these guidelines—even if they do improve indoor air quality and cut the risk of costly litigation?

To date, only a few states have chosen to establish code mandates based on the standard. Vermont's Residential Building Energy Code included ventilation requirements that took effect in January 2005. Still, even there the standard was not totally adopted. Minnesota adopted similar requirements. In California, by 2008, the state's energy code may include most of the ASHRAE 62.2 standard.

The EPA's new version of Energy Star, meanwhile, includes indoor air quality ratings that draw on some provisions of the ASHRAE standard. Importantly, though, EPA guidelines address issues associated with ductwork locations, infiltration, and cleaning. For example, air handling equipment and ductwork cannot be located in garages, according to Energy Star IAQ guidelines. For builders who are already Energy Star rated, the incremental cost of moving to the IAQ package is nominal. In fact, all of the required air sealing costs relatively little if the builder reclaims the value of sealed duct-work, pressure balancing, and controlled infiltration by downsizing the heating and cooling equipment. Real costs associated with upgrading these systems derive from training and monitoring the subcontractor base, not just additional materials.

Builders who choose to use indoor air quality as a “value-added sell” are rare, but one notable and successful example is D.R. Horton's Sacramento division, which made a business decision to build according to the American Lung Association's Health House program. Horton and others who build ahead of the curve have found that workable and affordable standards do exist. In addition, some builders employ the services of private resources like Ibacos, a Pittsburgh-based consulting firm that specializes in the practical implementation of building science improvements.

Most builders base their decisions on this issue on code. Risk-aversion ranks No. 2 among priorities, and third would be competitive positioning. The question for builders may be how much “selling contact” time they might leverage for healthy house systems, as opposed to propositions such as location, size, and decorating. Hopefully, the force of public awareness will gain enough momentum to create a successful selling proposition before our building codes catch up with the IAQ issues down the road.

Steve Gnau is a member of Associated Builder Solutions, a management consulting firm specializing in the home building industry. He has managed product development efforts in major home building organizations for 15 years.