The Head Carpenter is a character in Harvest Moon 64.
He runs the house extensions business in Moon Mountain. He can always be found at his home. He's a minor NPC who appreciates most gifts that are given to him, even though befriending him doesn't appear to do anything.
There are several building projects that you can help the Head Carpenter and his assistants with, including helping to build the bridge and the hot springs. Assisting with these projects faithfully will also help you to gain affection with all of the carpenters.
If you give him a mushroom, he will give you the recipe for Mushroom Rice.