With the cost of energy on the rise, It is a good idea to tighten the envelope of your home. Once you have reduced air leakage it becomes important to actively ventilate the home to maintain healthy air quality and moisture levels. This can be done by installing a Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV). We offer the RecoupAerator by Sterling. The State of Oregon allows a tax credit for installation of these units.
I have heard several people complain about having a tight house and how it is rotting down around their ears because it is too tight. The problem they are facing is two fold, The air barrier is in the wrong place and moisture levels are allowed to get too high and the vapor travels through the interior wall finish and through the insulation to condense on the inside of their cold siding where rot and mildew forms. Reduce the moisture levels with ventilation, reduce vapor movement with paints specifically designed to reduce vapor transfer and improve the insulation/air barrier.