When heating a home, the inside pressure is higher than outside, causing heat to leak out through any air gaps. Air sealing can reduce heat loss by 50% by limiting air escape. The benefits of air tightness include lower heating bills, reduced drafts, avoiding mold, and blocking noise and odors while increasing home value. New building guidelines require an air leakage assessment and achieving an air tightness of 10m3/hrs/m2 or better to save energy and achieve low carbon standards.