2015 IRC Building Codes: Are We Doomed to Repeat History?

By now, everyone should be aware of the moisture problems that exist in homes, and especially in stucco-clad homes.  Our own testing shows that 90% of stucco homes built in the mid-80’s through the 90’s have major moisture problems causing structural damages that most people can’t even see. While construction practices and codes have improved over the last 15 years, the old adage “history repeats itself” comes to mind when reviewing what the new 2015 IRC Building Codes are requiring in new home construction in MN.

In the mid 80’s, in order to lessen our dependence on overseas energy products, new “Energy Codes” were put into effect to reduce the amount of energy used to heat and cool a home. The code required northern homes to have a vapor barrier (poly sheet) installed behind the sheetrock to stop or restrict air flow through the walls. While this meant homeowners no longer needed to sleep with three down blankets during the winter, the full and the long term effects of a tighter home weren't completely understood when it went into effect. As it turned out, within five-to-ten years after construction, these tightly wrapped homes couldn't "breathe" and weren't able to dry out before the next rain. The homes just rotted away, often without any visual indication that anything was amiss.

If you look back in history, construction was booming in the late 80’s through the 90’s. Consumers were demanding larger, custom designed, more energy efficient homes. The homes became complicated systems that were not time-tested. A failure at any point in the system – a window, for example – could wreak havoc with the building structure because it couldn’t breathe. The energy code did not cause the damages, but significantly aggravated the issue if there was water getting into the walls.

At that time of expansion, builders could no longer keep up with the demand using their own construction crews; good experienced tradesmen were already employed and hard to find. Thus the use of sub-contractors became a norm in construction. As independent contractors, subs had their own agenda and bottom line to care for, and, due to the lack of oversight by the general contractor, jeopardized the system with their lack of knowledge or by taking short cuts that weren’t visible. Most structural damages can be blamed on “construction defects” caused by the builder or their subcontractor(s). 

Also during this time, city building inspectors were in high demand and short supply, and were not always making sure each house was built to minimum code. A common practice – partially due to a lack of liability – was for an inspector to very thoroughly inspect the first few homes for a particular builder, then back off once they felt that the work was being done properly. Unfortunately, inspector scrutiny didn’t return to a builder whose quality may have declined when he started to employ subcontractors. What resulted was tight, complicated homes built using poor craftsmanship, not being fully inspected and ending up with real moisture problems.

So, have we learned anything from the past? My crystal bald head says maybe not. 

The 2015 energy code is now requiring all new construction to be even tighter, having less than three air exchanges per hour. This means that even the vinyl homes that tend to “breathe” better may be as problematic as current tight stucco homes. If a home has a system failure and water enters into the wall cavity, it may be there for a long time before it dries out. A situation like this isn’t good for the health of the home, or its occupants.

All reports are saying that the rate of new construction is picking up. Contractors, and city inspectors, as well, are struggling to find experienced, skilled help. The recession that seriously affected the construction industry sent many of the old timers into retirement, and the good workers into other fields of opportunity. Just like in the 90’s, we may soon find ourselves in the same situation that led to sub-par homes built by subcontractors and not getting properly inspected.  

Will history repeat itself in this case? Or is my sense of Deja’ vu unwarranted? Only time will tell. I hope that we learned enough from the first go around to prevent it from happening again, but, just in case, make a note in your 2025 calendar to see if moisture problems are still happening. We won’t know until we test today’s homes in the future. 

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Moisture & Structural Assessments in Residential and Commercial Properties


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