If you are thinking about building a new garage, you should be aware of a recent change in code requirements. It used to be the case that an attached garage floor had to be 4 in. below the floor of the house. This was seen as a safety precaution, keeping spilled gasoline and fumes from getting inside.
But the widely adopted International Residential Code (IRC) does not require this step. Being able to set the house floor at the same level as the garage can be an easier and less costly process, but, as Lynn Underwood, a building code official in Norfolk, Virginia, notes in the October 2009 issue of the Journal of Light Construction, some building inspectors "never forget a code requirement." If you run into a code official who says you must honor this old obligation, tell him or her to take a look at the current IRC.
Comments
I have dealt with many code officials in my line of work and found out that the codes are minimum requirements but that the Authority Having Jurisdiction has the last say. So if they say that they want the 4″ step, then the builder is required to do so.