Plan PV with self-drawn roofs

The Self-drawn workflow is the manual fallback in the Planning step's 3D editor. You trace the building footprint, pick a roof type, set wall height and tilt, and lay modules over the result. Use it when drone photogrammetry or a usable external image isn't available, or when the building is simple enough that drawing it is faster than ordering imagery.

Before you start

• Open the customer's offer, go to the Planning tab, and open the 3D editor on the PV system (see Plan PV modules in the 3D editor for the full entry path).
• Have the rough building dimensions to hand, or be ready to read them off the Google Solar map material inside the editor.
• Know the real-world roof shape. The procedure forks on the roof type you pick after drawing: a hipped, four-sided roof (choose Normal roof), a gable, two-pitch roof (choose Gable roof), or a flat roof (choose Flat roof).

The Self-drawn workflow

Self-drawn is one of four paths in 3D planning. Reach for it when:

• Drone imagery isn't available for the address. See 3D drone photogrammetry for the imagery path.
• You don't have a usable external image to trace over.
• The building is straightforward enough that drawing the outline is faster than commissioning capture.
• No roof was seeded automatically for the building. Where a seeded roof already exists and is close but wrong, reshaping it is usually faster than deleting it and drawing from scratch.

All roof types share the same opening move: switch to Building mode, pick a map material that gives you a clean top-down view, choose Draw roof from the Quick Access menu on the canvas, and trace the outer edges. Where they differ is roof tilt, wall-height setup, and which roof features you can add. Pick the section below that matches the building.

Flat roof

On a flat roof, roof tilt isn't an input. You draw the outline, set an exterior wall height, and cover the surface with elevated modules.

Draw the roof

1. In Building mode, choose Draw roof from the Quick Access menu, or press D.
2. Trace the outer edges, clicking each corner in turn.
3. Close the shape at the starting point.
4. Choose the roof type Flat roof.

Adjust wall height and shape

Click the building. On the right, type the exterior wall height (e.g. 6 m) into the numeric field. Enter the building's real height: tall structures such as apartment blocks model at their full height. Move individual edges and corner points via the arrow handles. The whole building can be rotated, duplicated, and moved as one piece.

Set edge insets and exclusion zones

For the perimeter setback, enter the inset distance from the outer edge in the roof overlay. The inset is per edge, so you can set a larger setback on one side (e.g. for fire-code access) and a tighter one on another. Modules stay back from each edge by the inset you set.

For exclusion zones inside the surface:

1. Switch to Building mode and select the roof surface.
2. Add an exclusion zone and set its type (chimney, window, or other) and height.
3. Shape the exclusion zone footprint. Endpoints and sides can be moved afterwards, so complex shapes are possible.

Choose the layout type

On a flat roof you elevate the modules, and the panel group's layout type decides the arrangement. The four layout types are Horizontal, Vertical, Horizontal Two-Sided, and Vertical Two-Sided:

• A single-sided layout (Horizontal or Vertical) sets one row direction per module block. Use it for a south-facing tilt.
• A two-sided layout (Horizontal Two-Sided or Vertical Two-Sided) creates the paired east-west arrangement, with two rows of modules angled away from each other. You can set the two-sided tilt and the double-row gap between the two rows.

Cover with modules

1. Choose the module in the sidebar and place a group with Add panel group, or fill a roof side with Cover roof side.
2. Expand the module area via the row/column inputs in the Panel Overlay.
3. Set the tilt (e.g. 30°) and the gaps for the group in the Panel Overlay.
4. For the east-west variant, switch the layout type to a two-sided layout, then adjust the two-sided tilt, rows, and spacing.

Instead of placing module groups one by one, Cover roof side fills the roof surface automatically, respecting exclusion zones, dormers, and roof-edge insets. You specify elevation and spacing, then trim manually.

Gable roof

The gable roof is the most common roof type in residential planning. The workflow: determine roof tilt up front, draw the roof, set exterior wall height and tilt, then add exclusion zones and roof features.

Determine roof tilt first

Switch to the Google Solar map material for reference. It shows building outlines, trees, and shading context. The on-canvas measure tool (ruler icon) reads distances on the canvas. Enter the roof tilt you've measured or know into the per-edge tilt field; the tilt is a value you type in yourself.

Draw the roof

1. Switch back to a flat top-down map material.
2. In Building mode, choose Draw roof from the Quick Access menu, or press D.
3. Click the corner points of the roof one by one to trace the footprint.
4. Close the shape by clicking the first point again.
5. Choose the roof type Gable roof. If the ridge doesn't run along the longer side, use the Swap sloped sides action to flip which pair of edges carries the slope.

Set wall height and tilt

1. Click the building. Input fields appear on the right.
2. Enter the measured tilt (e.g. 46°, or your actual measured value) on the sloped edges. On a Gable roof the two sloped sides share the same pitch.
3. Set the exterior wall height. Use the Google Solar material as reference, and enter the building's real height: tall structures model at their full height.
4. Where one side of the building sits above the rest, such as a stepped eave, a split-level extension, or a lean-to against a taller wall, set that side's base-line height offset in the roof overlay.

Each side of a Normal or Gable roof carries its own base-line height offset. Raising a side's offset means that side's slope starts higher than the roof's base line; leave the offset at 0 for the sides that start at the base. The 3D preview re-renders as you go, so you can check the raised side against the real building before placing modules.

Add insets, exclusion zones, and roof features

For the perimeter setback, enter the inset distance for the roof edge, e.g. 25 cm, so modules stay back from the edge.

For dormers:

1. Add a dormer, either a pointed dormer (classic) or a flat dormer.
2. Place the dormer near the roof's ridge and drag it to the right position.
3. Correct distances by clicking the dimension and typing the exact value (e.g. 7.00 m instead of 7.05 m).

For chimneys and roof windows, add an exclusion zone and set its type (chimney, window, or other) plus its height. Existing dormers and exclusion zones can be duplicated, so identical features spread quickly.

Cover with modules

In Modules mode, you have three options:

• Add panel group: select a single module and place it on the roof surface by click.
• Cover roof side: Reonic fills the roof surface automatically, respecting exclusion zones, dormers, and roof-edge insets.
• Optimieren (optimise): where it's switched on for your account, each roof side carries a floating Optimieren button. It sweeps several placement strategies and settles on the one that fits the most panels on that side, showing the candidate layouts as it evaluates them. Ask your Reonic account manager if you don't see it.

Modules can also be placed outside the standard grid, e.g. on a dormer. Check substructure and shading per case.

Add offer snapshots

Before stringing, position the camera so the system is clearly visible and click Add view at the top right. You can save up to four custom camera viewpoints (plus one default) for the offer PDF's multi-view render.

Hipped and combined roofs

Hipped roofs and combined roofs are common in older residential buildings and agricultural structures. A hipped, four-sided roof is a first-class roof type: after drawing the outline, choose Normal roof, the default option in the Roof type menu. Normal and Gable roofs both carry per-edge tilts you can fine-tune to match the real geometry.

Check before drawing

• Street View: rough estimate of building height and tree presence.
• Google Solar: reference material for outlines and shading context. Use the measure tool for distances. Relative tree heights are also visible, and roof tilt is a value you enter yourself.

Draw and shape the roof

1. Switch to a flat top-down map material, then choose Draw roof from the Quick Access menu in Building mode, or press D.
2. Click the corner points and close the shape.
3. In the Roof type menu, choose Normal roof for a hipped roof. The 3D preview re-renders to the hipped shape immediately.
4. Set the exterior wall height and roof tilt. Each edge carries its own tilt entry, so you can adjust the hip slopes and the main pitches independently until the geometry matches the building. Each side also carries its own base-line height offset, for a building that steps up on one side.

Add dormers

• Pointed dormer: start near the ridge, then set position via dimensions.
• Flat dormer: place near the ridge. A flat dormer carries a height-difference value that can align it to the roof slope rather than sitting horizontal.

Identical dormers can be duplicated, so you only set up one carefully.

Add trees for shading

Trees are drawn similarly to dormers. Set height and width so the later shading analysis calculates realistically.

Build complex roof shapes from several roofs

A building with several roof faces (extensions, garages, agricultural U-courtyards) is drawn as multiple separate roofs, one structure each. Repeat Draw roof for each face and position them so they meet. Each surface stays separately editable, and you plan modules per roof face.

Cover complex roofs with modules

With many obstacles and tight surfaces, single-group placement (Add panel group) is usually better than Cover roof side. You decide more flexibly where a module makes sense. For orientation, switching between vertical and horizontal helps, e.g. fitting four modules on a dormer instead of two.

Things to know

• Enter the roof tilt manually. For gable and hip roofs, obtain the tilt from your own measurement or the building plans and type it into the per-edge tilt field. Switch to a flat top-down material for the actual drawing.
• The backdrop is a visual guide. The imagery you trace over is reference material for your drawing. The drawn geometry and tilts are what the solver uses, so trace carefully and verify the tilts.
• Roof type is picked after you draw. Draw the outline first, then choose Normal (hipped), Gable, or Flat. Gable is offered only when the outline is simple enough to convert.
• Duplicate, don't rebuild. Dormers and exclusion zones (chimneys, windows) can be duplicated. Set one carefully, then copy.
• Cover roof side is the speed lever for simple roofs. Use it to populate a roof side in one click, then trim around obstacles. On heavily obstructed roofs (hip plus dormers), single-group placement (Add panel group) gives more control. Both automatic fills, Cover roof side and Optimieren, work one roof side at a time, so a multi-face roof is filled face by face.
• Undo lives at the bottom-left. Especially useful when experimenting with per-edge tilts to shape a hipped roof.

Last updated on September 30, 2026