batt insulation

We've had most of the interior walls filled with batt insulation. We're using the insulation to help reduce sound transmission from room to room. We're expecting a 5 point increase in the STC rating (of sound transmission) due to the additional mass in the walls. The Johns Mansville fiberglas batts are made without formaldehyde, which is important for maintaining our health, and are made with glass that is at least 25% recycled.

The insulation has also produced some nice spatial effects...

that new house smell

Formaldehyde causes cancer. Architects and environmental activists have known this for a long time, which is why the indoor air quality portion of LEED requires us to use materials that do not include added formaldehyde. Yesterday, the federal government’s National Toxicology Program finally confirmed this fact in their latest Report on Carcinogens.