A dependable solar design starts with accurate site geometry and clear placement constraints. This guide explains how to model roof surfaces, place arrays, and account for setbacks, pathways, trees, and rooftop obstructions in Powerlily.
Start with reliable site information
Confirm that the design is centered on the correct property and review the available imagery, elevation data, parcel information, drone survey, and site measurements. Imagery is a useful starting point, but it does not replace verified dimensions where construction accuracy matters.
Build and review the roof geometry
Create or refine the roof planes that make up the structure. Powerlily supports automatic and assisted roof-plane workflows as well as manual editing for unusual buildings.
For each plane, review its outline, height, pitch, and orientation. Define the roof edges correctly because eaves, rakes, ridges, hips, and valleys may require different clearances. Use the 3D view to check how adjacent planes connect and to catch height or slope problems that may not be obvious in 2D.
Place the array
Select a roof plane and create an array using the intended panel. Choose portrait, landscape, or best-fit placement, then adjust spacing, stagger, and setbacks as needed. Smart fill can create a useful first layout, while panel-level editing, copy, multi-select, snapping, undo, and redo make it easier to refine.
Check that every module is actually supported by the intended mounting surface. Remove or reposition panels that cross roof edges, overlap another object, or leave impractical installation space.
Use company setback presets
Company administrators can create fire-code setback presets under Panel setbacks in quote settings. A rule set can include:
- A name and jurisdiction.
- Clearances for eaves, rakes, ridges, hips, valleys, and obstructions.
- Multiple conditional variants, such as a different ridge clearance when array coverage crosses a threshold.
- An effective date, version, and source link.
- A company-default setting for new designs.
The company default is applied when a new design opens. Designers can select another active preset or fine-tune the values for a particular project.
Choose the correct rule variant
Some codes have conditional requirements rather than one universal distance. Choose the variant that applies to the actual roof and array. The first condition in a company rule set is treated as its default, but that does not remove the need to review the project.
When a preset is applied, Powerlily saves the applied values and their source with the design. Later changes to the company rule do not silently reshape an existing saved design.
Apply perimeter setbacks and pathways
Use Apply Perimeter Setbacks to establish clearances from the classified roof edges. Add required fire pathways and keep-out regions where access must remain open.
Inspect the result instead of assuming every generated boundary is correct. Complex roofs, shared edges, unusual code conditions, and incomplete geometry may need manual refinement.
Add rooftop obstructions
Model vents, skylights, chimneys, HVAC equipment, and other rooftop objects that affect module placement or required clearance. Size and rotate each obstruction to match the site, then apply the appropriate obstruction clearance.
Do not use a generic obstruction as a substitute for correcting the roof itself. Roof planes should describe the mounting surface; obstruction objects should describe items located on or near it.
Add trees and shading objects
Add trees and vegetation that can materially affect the array. Position them carefully and use an appropriate canopy form and height. Review shadows across different times and seasons, not just the current view.
Include nearby structures or objects when they create meaningful shading or clearance constraints. The physical scene feeds the shading and production analysis, so unrealistic dimensions can distort the results.
Refine the array after adding constraints
After setbacks and objects are in place, review the array again. Use panel-level controls or rerun the layout to remove conflicts. Compare the revised module count and capacity with the target system size and the quote.
Final review checklist
- Roof outlines, heights, pitches, and orientations match the best available site information.
- Roof edges are classified correctly.
- The applicable setback rule and conditional variant are selected.
- Required pathways and keep-out regions remain clear.
- Obstructions are correctly sized, positioned, and rotated.
- Trees and nearby objects use realistic locations and heights.
- No panels cross edges or overlap restricted areas.
- The final module count and system capacity match the saved quote.
Code responsibility
Powerlily provides design and validation tools, but it does not determine which code provision applies to a project. Confirm current requirements with the authority having jurisdiction and qualified project professionals before using the design for permitting or construction.
