> The pacific northwest had major issues when OSB met the concept of "air tight" housing. No airflow in/through walls leads to condensation, mold and collapse o

> The pacific northwest had major issues when OSB met the concept of "air tight" housing. No airflow in/through walls leads to condensation, mold and collapse of many "engineered" wood products held together with glue. These are not indicators that air tightness is bad, but rather that people don't understand building science. Washington state (for one) has mandated air tightness levels (§R402.4.1.3) and testing (§R402.4.1.2): * https://sbcc.wa.gov/sites/default/files/2023-04/2021_WSEC_R_1stPrint-1_042623.pdf https://sbcc.wa.gov/sites/default/files/2023-04/2021_WSEC_R_... Air tight passive houses are built without issues in the US PNW: * https://phnw.org https://phnw.org * https://hammerandhand.com/high-performance/passive-house-builders/ https://hammerandhand.com/high-performance/passive-house-bui... * https://asiri-designs.com/f/how-to-design-an-energy-efficient-home-in-the-pacific-northwest https://asiri-designs.com/f/how-to-design-an-energy-efficien... The province of BC is mandating near-passive house levels of air tightness: * https://www.energyadvisor.pro/airtight-energy-advisor-contact-us/bc-step-code-builders-chart-energy-advisor/ https://www.energyadvisor.pro/airtight-energy-advisor-contac... * https://energystepcode.ca/how-it-works/ https://energystepcode.ca/how-it-works/ * PDF: https://www.bchousing.org/publications/Illustrated-Guide-Achieving-Airtightness.pdf https://www.bchousing.org/publications/Illustrated-Guide-Ach... Build your structure according to how physics works and it will work just as well from the tropics (IECC Zone 1) to the arctic (IECC Zone 8): * https://buildingscience.com/documents/insights/bsi-001-the-perfect-wall https://buildingscience.com/documents/insights/bsi-001-the-p... * https://basc.pnnl.gov/images/iecc-climate-zone-map https://basc.pnnl.gov/images/iecc-climate-zone-map Air tightness is coming to building codes everywhere, and if you can't make it work then you shouldn't be building because you are incompetent: * https://www.iccsafe.org/building-safety-journal/bsj-technical/significant-changes-to-air-leakage-in-the-2021-international-energy-conservation-code/ https://www.iccsafe.org/building-safety-journal/bsj-technica...