tennisgun

Is there a global way to offset all elevations in the plan by 5'? Completing design for a home on a 10-15 degree sloping lot - front to back, and 5 degrees slope - left to right (main house, breezeway and garage in line laterally with front). Mitigating cut and fill work, the attached garage is now 4-5 ft lower than main floor. Garage is about zero elevation and main floor at 57". Would like to set main floor to 0" (to make building calculations simpler) and offset all elevations (absolute and relative to floor) including all plot elevations. Thank you Erik