Most newly constructed homes come with a 12 or 24 month warranty from the builder. This provides piece of mind for home buyers that their new home isn't going to fall apart once the contract is signed. Unfortunately, sometimes things still break or were not done properly the first time.
This is where a 10 month warranty inspection comes in. By having the home inspected after you have lived in it for almost a year provides a chance to identify any new issues or developing problems that previously were invisible. Sometimes it takes a few months of running a faucet to see that the plumbing is leaking behind the wall or a few big rain storms to see that a roof penetration is not sealed properly. By catching these issues early on while still under warranty can save the home owner thousands of dollars down the road.
Why 10 months and not 11 months? This is mostly because builders are busy and so are you! That gives you a full two months to contact the builder, have the work completed and some extra time in case something isn't done right or life gets in the way.