Retrofit of Solar Panels to Existing Buildings  

I am interested in other engineers opinion on the retrofit of the solar panels to existing buildings which, currently, can be done without a building consent and consequently without any engineering input.

Since the solar panels weight between 10 and 20kg/m2 and are commonly installed on the whole (or almost whole) area of the existing roof, they have the potential to double the weight of the roof and consequently seismic weight and demands on the stability system for earthquake loading.

This can be especially onerous for industrial or farm sheds which typically have very light roof, making the relative increase very significant.

Whilst such sheds will, typically be wind governed in the “across” direction they are ore more often than not governed by seismic loading “along” the building.

I personally find it concerning that such a significant additional load for the bracing system can be added to the existing building (often old and already lacking in seismic resistance required by new standards) without any scrutiny from a suitably qualified structural engineer.

Interested what others think and if/how this could be raised with the TAs