There's more than one way to find out how a plot slopes. Each suits a different stage. Here's an honest comparison, including when we're not the right choice.
| Measured topographic survey | OS Terrain 5 | Free public LiDAR, DIY | PlotLevels | |
|---|---|---|---|---|
| What it is | A surveyor measures the site on the ground and draws it up in CAD. | Ordnance Survey's licensed height model: a 5 m grid and 5 m contours, made by photogrammetry and updated quarterly. | Download the open LiDAR from the Scottish Remote Sensing Portal and process it yourself. | The same open LiDAR, cut to your boundary and turned into contours, a CAD pack and a plain-English report. |
| Cost | About £480–£1,152 for a small residential plot in Scotland (under ¼ acre), indicative Q3 2026 figures from BestBuilders.1 | Premium product. It's not free under the public-sector agreement and is bought through an OS partner. Some partners sell small tiles from a few pounds.2 | Free data (Open Government Licence). Your time and GIS software are the cost.3 | From £29 for the CAD pack, or £49 for the full report (one-off price). Free preview, no account needed. |
| How long | BestBuilders says fieldwork is normally half a day to a day, with the CAD drawing 3–7 working days later. Add the time it takes to book a surveyor.1 | Depends on the partner. Usually a download once ordered. | Hours if you know GIS. Longer if you're learning. | Automated: about 3–5 minutes in our test runs. |
| Accuracy | The best of the four. Measured on the ground to a specification you agree with the surveyor.4 | OS quotes typical accuracy of 2 m RMSE or more. Coarse for a single plot.2 | The same as the LiDAR survey. It depends on the phase and the ground cover. | The same as the LiDAR. No vertical accuracy figure is published in the source metadata, so we don't claim one. Expect bigger errors under trees, near buildings and on steep ground. Shows the date the area was flown. |
| Shows | Ground levels plus features: walls, kerbs, drains, trees, manholes, buildings. | General ground shape only. | Ground shape. Features depend on what you extract. | Ground shape, slope and aspect, plus public map layers. Not drains, culverts or recent works. |
| Skills needed | None. The surveyor does it. | GIS or CAD. | GIS (for example QGIS), plus knowing which LiDAR phase and tiles to choose. | None. Draw your boundary on a map. |
| Best for | Detailed design, building warrant drawings, setting out, anything that needs a surveyor to sign it off. | Large-area or landscape studies already using OS data. | Confident GIS users with time to spare. | Deciding whether to buy a plot, early sketches and briefing your architect. |
Commission a measured topographic survey before detailed design, before building warrant drawings, for setting out foundations or drainage, where a level difference of a few centimetres matters (thresholds, access gradients, retaining walls), where the ground has changed since the LiDAR was flown, or wherever your architect, engineer or lender asks for one. PlotLevels levels are a good way to decide whether a plot is worth paying a surveyor for. They don't replace one.
PlotLevels gives levels from Scottish Government LiDAR, tested to ±0.14 m typical on open ground (95% within ±0.28 m). It's a desk-based report, not a flood risk assessment or planning advice.
Checked 23 October 2026. Prices and products change: check the sources. PlotLevels prices are shown as currently set on the pricing page.