The intent of this credit is to reduce exposure to indoor pollutants originating from an adjacent garage. Our architect initially drew our garage as detached — he likes the scale and proportion of a house better without a garage. Having a detached garage, or no garage at all, would have given us three points. Seems like an easy 3 points! BUT we live in Minneapolis, and if anyone can have an attached garage, anyone in their right mind would choose that. So, given that we do have a garage and it is attached, here are the strategies to reduce our exposure to pollutants:
10.1 No HVAC in the garage. This is a prerequisite, because you shouldn’t be exchanging air in the house with air in the garage. Our HVAC system is located in the basement mechanical room, which is more typical of homes in this area. Apparently in some areas of the country, people more frequently do locate their HVAC system in their garages, so this may be a more difficult prerequisite for them. (It never occurred to anyone on our design team to locate it in the garage.)
10.2 Minimize Pollutants from Garage. For two points, we need to have tightly sealed shared surfaces between the garage and our home, in all of the following ways:
1. In conditioned spaces above the garage: seal all penetrations; seal all connecting floor and ceiling jois bays; and paint walls and ceilings (carbon monoxide can penetrate unfinished drywall through diffusion).
2. In conditioned spaces next to the garage: weather-strip all doors; place carbon nomoixde detectors in adjacent rooms that share a door with the garage; seal all penetrations; and seal all cracks at the base of the walls.
We did all these things, although I didn’t know painting the garage would help seal off carbon monoxide. I also don’t understand what they mean by “seal all cracks at the base of the walls.” What cracks? There were none; I suppose I should appreciate our builder for that. We get the two points here.
10.3 Exhaust Fan in Garage. We could get one point if we had installed an exhaust fan that is rated for continuous operation and designed to either run continuously or with an automatic timer control linked to an occupant sensor, light switch, garage door opening-closing mechanism, carbon monoxide sensor, or equivalent. This seems like a good idea, but we did not do this. We never even discussed it. The fact that we have two hybrid cars makes me feel better, though, because they are both usually running on battery when we drive in and out of the garage.
This is the last credit in the Indoor Environmental Quality section, and it seems to be quite comprehensive, with one exception. The one BIG piece of healthy indoor air quality has to do with cleaning chemicals. The EPA estimates that indoor air quality is 3-5 worse than the outdoor air, and that is partially due to harmful cleaing agents. I’m not sure how LEED could incorporate cleaning chemicals as part of its certification process, because it is yet another piece that comes up once people live in their home — a common theme of commentary for a “green” home. I would, however, debate the critics that LEED has to do mostly with energy. While Energy & Atmosphere has the largest share of possible points (38), Indoor Envrionmental Quality is third, with 15%, just behind Sustainable Sites, with 16%. And in the long run, reducing energy will improve our health — less coal and fossil fuel burning is directly linked to outdoor air pollution.