Bath exhaust fan issue
Assuming you are in the US, the cost to correct it likely falls under the limits for Small Claims Court. So you could request a remedy from the builder and if they refuse, sue them in Small Claims under &quot;implied warranty&quot;, meaning it is implied that something you buy will do what it is intended to do. Exhaust fans must exhaust, this one never did, so the length of time, although possibly subject to a statute of limitations, should not be a factor. In many places the statute of limitations is 3 or 4 years, others might be 7, so get on it!
This of course assumes that the builder is still a viable business entity.