Plan PV on an uploaded image (architect's floor plan)

External image is one of four building sources in 3D planning, alongside drawing the roof yourself, ordering a drone photogrammetry capture, and starting from Google Solar imagery. Reach for it on new builds where no aerial data exists: with a dimensioned floor plan you can still draw the building accurately. This page covers what's specific to the external-image source. The roof drawing and module placement follow the same path as the other sources.

Note: 3D planning is the residential planning path. On a commercial offer, turn on the 3D editor for the variant you want to use it on.

Before you start

• Open the customer's offer and switch to the 3D planning tab.
• Have a dimensioned architect's floor plan as an image file, with at least one known real-world distance you can read off it.

Upload the floor plan

1. Open the 3D editor and find the Custom Images section in the sidebar (the same imagery family as the Own image tile in the Layers panel).
2. Click Upload image. In the Upload modal, drag the file in or click to browse. The uploader accepts image files.
3. The image appears in the gallery as Image 1, sitting at a default scale and position over the scene. Each further upload adds Image 2, Image 3, and so on.

Scale the image with a reference line

A freshly-uploaded image has no real-world scale. The reference line fixes that, so a roof you trace over it comes out the right size. You set scale, rotation, and position in one step by drawing two lines.

1. In the gallery, click Configure on the image. The view switches to a straight top-down (orthographic) camera so you draw on a flat plane.
2. Click Align with reference line. If the image already carries manual transforms, a prompt warns that the current transformations are reset. Click Continue to proceed, or Cancel to keep them.
3. Draw the first line in the image, along a feature whose real length you know, such as across a ridge or an exterior wall. Click one end, then the other.
4. Draw the second line on the ground plane, representing that same real-world distance at true scale.
5. Reonic computes the scale, rotation, and position automatically from the two lines. It stretches and rotates the image so the in-image line matches the ground-plane line.

Pro tip: Get the two lines right and the image lands aligned, scaled, and oriented at once. There's no scale factor to type.

Fine-tune position, rotation, and opacity

After the reference-line align, the image's detail view exposes manual transform controls:

• Opacity (slider, 0 to 100%) — drop it to around 30 to 50% so you can see your drawn roof and the image at once. Raise it to read fine detail.
• Rotation (slider, 0 to 360°) — spin the image flat on the ground plane to line it up with the scene's north.
• Scaling (number input) — multiply the image size directly if you need a manual nudge after the reference-line scale.
• Position (X) and Position (Y) (number inputs, in metres) — slide the image so it sits under the building.

The detail view also shows the resulting Image Width and Image Height in metres, so you can sanity-check the scaled image against the real building dimensions.

Pro tip: Draw at around 40% opacity so you can trace the floor-plan edges while keeping the background visible for context.

Draw the building and place modules

Once the image is scaled and positioned, switch to Building mode and draw the roof tracing the image, then place modules. The drawing and module steps are identical to the self-drawn source, so see the "Plan PV manually with self-drawn roofs" page for the per-roof-type walkthrough. Save with Ctrl+S. The custom image stays with the offer and carries over when you duplicate a variant.

Things to know

• A floor plan shows only the outer edges. Add roof shape, exclusion zones, and shading objects (trees, neighbouring buildings) yourself from the plans or an on-site walk-through.
• The uploaded image is visual reference only. The roof and obstacle geometry you draw is what feeds shading and production, so trace carefully and verify the tilts.
• Re-running Align with reference line after you've hand-tuned position, rotation, or scale resets those transforms first. Confirm before proceeding.
• External image is the right source when no aerial data exists. When Google Solar or drone imagery is available for the address, those give the roof geometry directly. See the "Start a PV plan from Google Solar imagery" page.
• To switch between two reference images, hide one with the eye toggle. Drag the gallery handle to reorder which image sits on top when several are visible.

Need help?

• Step-by-step questions about this flow → contact your Reonic account manager.
• Feature requests or something missing → send a note to your Reonic account manager.
• Bug reports → include a screenshot and the URL where it happened in your support email.

Last updated on August 4, 2026