Skip to content
GIMLabsDocs
Request a trial

Overlays and layers

Bring shapefiles, GeoJSON, images and PDFs onto the map, and switch on reference layers - geology, radon, coal mining, historical maps and your company's own.

On Pro, you can bring extra map data onto the base map - your own files, reference layers such as geology, radon and coal mining, historical mapping and your company's own WMS layers. Each is a layer you can show, hide and fade.

A Pro feature

Overlays and layers are Pro features; adding overlays also needs a role that can edit the map.

Overlays

The Overlays layer drapes your own data over the map:

  • Vector - upload GeoJSON or shapefile data.
  • Raster - upload an image or PDF to position over the map, with crop, rotate and transform tools.

Each overlay has its own opacity, visibility toggle and style.

Overlays are scoped to this project by default. From the overlay's options menu you can make one a configuration overlay so it shows on every project that uses the same configuration - these are marked with a globe on the overlay's row.

Positioning a raster overlay

Unlock a raster overlay to reveal its handles, then:

  • Move - drag the middle of the overlay.
  • Resize - drag a corner to scale it (aspect ratio is kept); hold Shift to stretch it freely. Drag an edge to stretch one side.
  • Rotate - drag the rotate handle; hold Shift to snap to 15 degrees.

Undo and redo your changes with Ctrl+Z and Ctrl+Shift+Z, or the undo/redo buttons on the overlay's row.

Align with two points

For an accurate plan or drawing, you can place it by matching two known points rather than dragging by eye. From the overlay's options menu (the ... button) choose Align with 2 points, then:

Pick a feature on the image

Click something you can identify on the overlay - a building corner, a survey marker, a grid intersection.

Place it on the map

Click where that feature actually sits on the base map.

Do it again for a second feature

Repeat for a second point. On the last click the overlay moves, scales and rotates so both features land on their targets.

The image keeps its shape (it is not skewed), so this works best with accurate, to-scale drawings. Press Esc or Cancel to stop; Ctrl+Z undoes it.

Reference layers

The Reference Layers panel holds published map data you can switch on over any project. Each layer has an on/off switch and an opacity control, and you can drag them to change which draws on top. The publisher is credited on the map while a layer is on. Where the service supports it, click the map to see the feature's details.

  • Geology and environment - BGS bedrock, superficial and artificial ground geology, borehole records, hydrogeology, soil parent material, historic landfill, source protection zones and radon (the BGS Indicative Atlas of Radon). Click a radon square to read its potential band and what it means.
  • Coal mining - the Mining Remediation Authority's Development High Risk Area, Coal Mining Reporting Area, mine entries, past and probable shallow coal mine workings, and surface mining.
  • Historical maps - historical and geological base mapping beneath your data.

Your company's layers

If your company uses other WMS services, they can sit in the panel too, under Your company's layers, on every project. A Super Admin adds them in OS under Settings > Map layers: paste the service's address, pick the layers you want, and give each a title and credit. They switch on, fade and reorder like the built-in ones.

Last updated 15 October 2026