Sec. 7. "Construction" means any of the following:
(1) Fabrication of any part of an industrialized building system or mobile structure for use at another site.
(2) Erection or assembly of any part of a Class 1 or Class 2 structure at the site where it will be used.
(3) Installation of any part of the permanent heating, ventilating, air conditioning, electrical, plumbing, sanitary, emergency detection, emergency communication, or fire or explosion suppression systems for a Class 1 or Class 2 structure at the site where it will be used.
(4) Work undertaken to alter, remodel, rehabilitate, or add to any part of a Class 1 or Class 2 structure.
(5) Work undertaken to relocate any part of a Class 1 or Class 2 structure, except a mobile structure.