Code violations are some of the most frequent sources of lawsuits following a construction project or renovation — mostly because the owners of the property don’t know that the violations are even there until the building fails an inspection.

Here are some of the code violations you need to be wary of in your own projects:

Electrical errors

Did you upgrade your electrical box or the circuits? It’s often done and always a good idea — but mixed voltages, too many wires to a switch and splices can cause serious safety concerns. You can bet that the first place a home inspector will look is inside that box to see if everything’s up to code.

Ventilation errors

These are most common in bathroom renovations, but they also get overlooked in mudrooms, workshops, attached garages and laundry rooms. Improper ventilation can lead to mold and rotting wood — and it can cause harmful fumes to back up into your house that could even put your life in danger.

Water heater errors

Another huge issue tends to be mistakes made with water heaters. Contractors may skip out on the expansion tank that is used to relieve excess pressure in the tank, and that can lead to explosions. An improperly fitted temperature and pressure relief valve is another common issue.

Safety code errors

Finally, there are all kinds of mistakes that can generally leave a home less-than-safe. That includes not having shatter-proof safety glass in windows that are by the stairs, forgetting to install handrails on stairwells inside or out and omitting smoke detectors and radon detectors.

If your contractor didn’t live up to expectations — and the remodel or addition on your home failed inspection, you may have legal options. Find out more about what you can do to recoup your losses and have things fixed.