Most companies in our union do both. The two main groups of work are Service and New Construction. Repair would fall under service work as well as installing things in finished buildings, preventative maintenance, etc. Right now I'm doing new construction. I hope to get to do service work at some point, though we always have a lot of new construction in this area. I get assigned to a new company every year while I'm an apprentice so there is a chance I'll get to.