Fire Setbacks

Fire setbacks are a safety standard implemented by state, and local regulating bodies. fire setback (or just setback for short) are non-negotiable but the rules vary from city to city and state to state. For example the entire state of Massachusetts does not require any set backs at all, and in Virginia Beach they are also not required but may be required in other parts of Virginia.

Edge Type
Generally speaking, the size of a fire setback is defined by the edge type of a roof.

Fiddling
There are some generally accepted exceptions when it comes to where setbacks have to be located in relation to an edge. A solar designer can move the setback onto the other side of the edge if that may result in a more favorable design. For example: If a solar designer is working on a design and (s)he thinks that if there were no set back on the hip of a roof he would be able to fit an additional panel on the west side of a building but lose a panel on the north side of a building, then he should make that trade because it results in gaining a higher performance panel. This can be achieved by removing the the 18 inch (1.5ft) setback on the western roof and instead have a 36 inch (3ft) offset on the shared hip on the north roof. NEEDS IMAGE EXAMPLES.

Solar designers should keep in mind that this cannot be applied to the ridge of a roof.