Section R903.4 of the IRC is amended to add the following:

R903.4.2 Gutters and downspouts.

All roofs sloped to drain over roof edges shall have gutters and downspouts. All downspouts shall have at least a five-foot splash block or a five-foot downspout hinged section to direct water away from foundations.

Exceptions:

(1) On roofs having a projection beyond the wall of the building of at least four feet, gutters may be omitted except at entrances to and exits from the building.

(2) Gutters are not required on patio covers, awnings, greenhouses, and sheds which do not receive drainage from the building roof.

(3) Gutters are not required on roofs which drain onto another roof which complies with this section.

Downspouts shall not be constructed in such a manner as to drain across primary walkways serving any type of residential unit or tenant space, nor shall they discharge in such fashion as to divert drainage onto adjacent properties.