Plan for future additional load to make sure the roof can structurally support dead load such as the racking and panels, wind load, and snow load. To help with this process, communicate the potential additional load with your roof truss suppliers, and document this structural information on the appropriate plans. Designing and documenting what additional load is possible has the potential to negate the need for a future contractor to sister rafters or make other structural adjustments.
In construction plans, clearly mark the roof area where the future potential array could be located, where the dedicated wall space in the utility room will be, and where other balance of system components will be placed. Doing so can decrease future planning time make it easier for future contractors to design and execute a solar installation.