An apartment building of 10+ units will generally benefit from having an on site laundry facility. Residents enjoy the convenience of doing laundry in their own buildings and owners enjoy the extra revenue. The downside, of course, is the repair cost, which can add up once the machines fall out of warranty. Service technicians for a washer or dryer can be in excess of $200+ per incident, never mind the lost revenue if a machine is out-of-order and waiting for new parts.