addtext wrote:Does an attached garage require a man door to the exterior?
No, the IRC (International Residential Code) does not require a person door from a garage. A garage is not considered "habitable space" and is used for "vehicle storage", which is its primary intended use, so the vehicle door which is provided for that purpose is all that is required.
Another reason a person door is not required from the garage is that the garage is not allowed to be considered as an egress path, one may not be required to egress from the living area through the garage to the outdoors.
However, before you close that door up, I recommend you check with your local building department to verify they do not have a local requirement for such a door (they should not require such a door for the reasons given, but it is best to verify that with them).
Also, if you keep the door locked and simply discontinue using the existing door, then place your shelves in front of the door, no one from inside the garage will be able to access the door (thus the door being there is not a problem) and, because the door is locked, no one from outside will be able to access the garage through that door (thus the door being there is not a problem).
This allows the door to remain, and when you go to sell, your buyer may want the door there.
Additionally, removing the door and making the wall water tight and weather resistant will be a problem with many types of siding, as well as making the new siding match in with the existing siding so as to not "show the outline of the door".
Personally, if I did not want the door, I would simply remove the lock and handle set and install a dead bolt from the inside with a blank cover over the outside, this eliminates the outside door knob and anyone trying to get in, yet, locks the door with the dead bolt lock. Then I would put the shelving in front of the door, keeping the removed lockset in a bag hanging from the dead bolt lock where you would be able to find it in 5 years and place the door back in service when needed or wanted by you or others.