I have a mature cedar elm with about 25' branch diameter/drip line. Will it hurt or kill tree if foundation for house addition is about 5' away from trunk? Foundation slab would cover about 30% of drip line, and at foundation's edge would be 24" deep, necessitating cutting of some mature roots. It has had a driveway slab 4' from trunk on the opposite side of planned slab for 20+ years and shows no signs of harm, is healthy as can be and equally developed in all directions. Existing slab would be removed, so that side would be earth again (basically flip-flopping a slab from one side to the other). OK to do or bad idea? Don't want to remove tree as architect has suggested.