Friday, May 8, 2015


When you want to install roof solar panels or photovoltaic panels, you need a building permit. That sounds ok, right? After all, you add something to the building, and the cost is over $500.00, the threshold for which you need a permit. The Department of Building and Safety requires, in order to prepare plans, that you go to a structural engineer, make calculations, pay fees to the city (and to the structural engineer), and then you receive your permit.

The problem with this approach is that photovoltaic panels are extremely light. Average weight is about 3-5 lbs/sq. ft. Every roof is, and always has been, designed to have a live load of 16-20 lbs/sq.ft. for most residential buildings. When you install these panels you add the weight of this 3-5 lbs/sq.ft. On the other hand these areas will never receive any live load, nobody will walk on top of these solar panels, they would break. Therefore you actually decrease the total load - live load + dead load - for the roof. Why bother to make calculations for something which is less then what it was originally designed for? (The seismic considerations are negligible compared to the total weight of the building.)

Thank God, the City of Los Angeles recognized this and streamlined the process. Instead, you can now get a permit online, without waiting days and many times weeks, bypassing the Department of Building and Safety, as well as the costly structural engineer.

Kudos to the City recognizing this situation, cutting through the red tape and expense, making the installation of a roof solar photovoltaic system more economical and faster for home owners!