Abstract: Apparatus and method for raising a roof including at least two lifting beams which are generally parallel to the peak or highest point of the roof and at least two pairs of lifting towers which are arranged about the building. Each pair of lifting towers has one tower disposed along one face of the building and the other tower disposed along the opposite face of the building. The lifting beams are interconnected with the roof portion and the lifting towers; the selected roof portion is then severed from the building and lifting means raises the lifting beams and the attached selected portion of the roof. After installing walls under the raised portion of the roof, the roof is lowered and attached to the newly constructed walls to form the additional expanded space of the building.