There are key similarities and differences between residential and commercial downspouts. They are similar because their core purpose is to drain water from within the gutters and route it safely to the ground.
While residential gutters will typically route water away from the home and into the landscape, commercial properties don’t always have that luxury. Therefore, rainwater can route into pumping systems, buried downspouts, or underground drains. Depending on local regulations, commercial downspouts may also route rainwater into the sanitary sewer or storm drain system. Most of this involves pre-construction planning.
While we typically balance aesthetics and functionality goals in residential guttering, commercial downspouts (and their gutters) lean more towards the functionality of controlling high-volume rainwater. Yes, we build downspouts to match appropriately with the gutters, but larger or oversized systems are chosen for commercial properties.