At least in California, and I suspect most of the country, "Building Inspectors" from the city, county, ? are also not liable. If your house burns down because they "missed that", too bad, it's on you. Between plan check fees (having a tech check to see if your registered, licensed architect, engineer, or other design pro's did their work right), to the actual inspection fees, a hell of a revenue stream for local government's.
Just my $0.02 worth (inflation adjusted to $0.012475)
Lets make sure we understand the two different 'inspectors'.....
First, you have the "Home Inspector"....this is the guy that the potential home buyer gets to inspect the house prior to closing. As slghmmr noted, a good inspection report can save a buyer from buying a bad house...
Then we have the "Building Inspector".....this is the guy that works for the city or county and inspects projects as they are under construction.
I am currently in the process of adding on a 2-story addition to my house. We just completed plan check and pulled all of our permits.....
I personally think LA county has it's **** together.....at least building and safety does.
The architect I used is good...real good....before he was drawing on paper, he was swinging a hammer building houses....has been in business for years....on this go-around with plan check, the checker went through the drawings in great detail. As anyone would expect, an architect is going to reuse drawings...especially things like notes.....it's the same from job to job, on the address changes. Well, this checker read everyone of those notes and found a few 'typos'....and found a couple of incorrect dimensions.....my architect was impressed with the detail of checking.
When it was all done...plan check was about $1200.....all the permits cost about $2000. But, I am pretty confident that my addition is not going to fall down....and...when it's all down, my existing house is going to be a lot tougher than before. If the 'big one' hits...I think I'll be just fine.
Regarding "Building Inspectors". I like the ones the county has. They take the time to explain things to me....if I have a question and they don't know the answer, the find out. A few years ago when I was doing the kitchen, I had a question about my vaulted ceiling. Because it was not real clear how I was explaining it on the phone, the guy said he would come out and have a look. Next day he stopped by...spent 5 min looking at what I was doing....suggested one change and went on his way.
Some people think the permit fees are just a money maker for cities and counties....I don't agree....I think the money is worth knowing that something is built right.
Disclaimer.....there is an issue with one of the cities here....inspectors were taking bribes....those inspectors are now looking for jobs.....the funny part....they took a total of less than $6K to look the other way....I'm glad LA County is not that way.....