My house was built in 08 how long does it take to settle

In truth it can take a lifetime depending on the foundation. All homes unless anchored to bedrock tend to move a little even from weather. The ground rises and falls with the amount of water it contains.

It mostly depends on the type of soil and where you live. I agree with califdadof3, house continue to settle for many many years but most is done in the first 12 months and the next 12 is mostly the end of the issue, BTW, tell us what is your issue, why do you ask?