Code violations happen. They do not have to, though, and the better the understanding builders have of each violation and its cause, the better their chances of avoiding them.

The National Association of Home Builders released a survey of building officials in 2013, detailing the most common building code violations and the reasons why they occur. At the time of this writing, it is the most recent survey on that topic.

The study asked building officials what the three most common violations were of the following codes: plumbing, mechanical or fuel gas system, electrical, energy, deck-related and common life safety. Overall, general design and accessibility issues were the most frequent offenders when it came to code violation, and violations were more likely to occur in areas with populations of more than one million.

More often than not, code officials felt that workers frequently ignore manufacturers’ installation instructions. Another common cause cited was a simple lack of code knowledge by contractors. Cost-cutting shortcuts were also cited as often resulting in code violations.

Plumbing code violations

Of those surveyed, 40.8 percent said improper notching, or boring of framing, was the most common violation; 37.7 percent cited improper or missing nail plates, and 29 percent pointed to improperly supported pipes.

Mechanical or fuel gas system violations

At 36.6 percent, noted inadequate combustion air or makeup air issues were most common; 34 percent cited improper notching or boring of frames; and 30.9 percent cited improper clearance for combustibles.

Electrical code violations

Thirty-two percent said a grounding issue was most common, while 28.6 percent said improper labeling of circuits occurred most frequently; 27.6 percent said improper GFCI protection was commonplace.

Energy code violations

Of respondents, 35.8 percent cited improper sealing of penetrations through exterior walls; 28.1 percent noted improper duct sealing; 27.3 percent cited improper installation of insulation around wiring and piping.

Deck-related violations

The most common was improper or inadequate ledger connection to the house at 62.2 percent; 60.7 percent of respondents blamed improper guardrail or handrail installations, and 43.7 percent said the deck in violation did not conform to the approved plans.

Life safety code violations

Just over half of respondents noted a failure to install correct glazing in required hazardous locations, while 47.5 percent pointed to inadequate egress and 46.5 percent cited improper installation of smoke detectors.