What Does a Topographical Survey Drawing Show?
A topographical survey drawing (topo drawing or land survey drawing) captures all visible physical features of a site in their correct positions and levels. Here is what is typically included.
What a Topographical Survey Drawing Shows
Boundary and Ownership Features
| Feature | Description | | --- | --- | | Boundary walls and fences | Positions relative to OS grid | | Gates and stiles | Access points | | Hedges and ditches | Ownership boundary indicators | | Railings | Boundary demarcation |
Ground Levels and Terrain
| Feature | Description | | --- | --- | | Spot heights | ODN levels at regular intervals | | Contour lines | Derived ground level curves | | Breaklines | Changes in gradient | | Level changes | Banks, slopes, retaining walls |
Buildings and Structures
| Feature | Description | | --- | --- | | All buildings on site | Outline, eaves, ridge positions | | Outbuildings and garages | Full positions | | Retaining walls | Heights and positions | | Bridges and culverts | Structures crossing watercourses | | Temporary structures | Site cabins, scaffolding |
Trees and Vegetation
| Feature | Description | | --- | --- | | Tree positions | Accurate X, Y coordinates | | Canopy spread | Diameter at survey date | | Species | Common and botanical names | | TPZ radii | Tree Protection Zone circles | | HAG heights | Height above ground level |
Services and Utilities
| Feature | Description | | --- | --- | | Manholes | Positions, rim levels, invert levels | | utility poles | Electricity, telephone, lighting | | Cable and pipe routes | Surface evidence only (PAS 128 for buried) | | Overhead lines | Positions and heights |
Roads, Paths and Hardstanding
| Feature | Description | | --- | --- | | Carriageway edges | Kerb lines | | Footpaths | Public and private | | Parking bays | Line positions | | Hardstanding levels | Impermeable surfaces |
Drainage
| Feature | Description | | --- | --- | | Surface water features | Swales, ditches, watercourses | | Drain heads | Surface water collection | | Soakaways | Surface water drainage | | Outfall positions | Connection to public sewer |
What Is NOT Shown on a Standard Topographical Survey
| What Is NOT Included | Alternative Survey | | --- | --- | | Buried services and cables | Utility detection survey (PAS 128) | | Underground drainage | CCTV drainage survey | | Beneath-ground structures | Ground investigation | | Subsurface levels | Geotechnical survey | | Legal boundaries | Land registry plan + boundary survey |
Survey Levels and Coordinates
| Data | Standard | | --- | --- | | Horizontal | OS National Grid (EPSG:27700) | | Vertical | Ordnance Datum Newlyn (ODN) | | Units | Metres to 3 decimal places |
Drawing Format
| Format | Use | | --- | --- | | DWG (AutoCAD) | Design, editing, coordination | | PDF | Review, submission, reference | | 3D DXF | Civil engineering, earthworks | | CSV levels data | Drainage design, cut/fill |
Drawing Scales
| Application | Typical Scale | | --- | --- | | Planning submission | 1:200, 1:500 | | Design development | 1:200 | | Construction | 1:100, 1:200 |
Frequently Asked Questions
Q: Does a topographical survey show the boundary?
It shows boundary features (walls, fences, hedges) in their surveyed positions. It is not a legal boundary determination — instruct a separate boundary survey if needed.
Q: Does a topographical survey show buried services?
No — a standard topo survey shows surface evidence only. Commission a PAS 128 utility detection survey for buried services.
Q: How are levels shown?
Spot heights (numeric ODN values) at key positions plus contour lines where specified.
Q: What coordinate system is used?
OS National Grid (EPSG:27700) with vertical datum to Ordnance Datum Newlyn.
Q: Can I get just a site plan without levels?
Yes — specify your requirements when booking. Levels can be omitted for simple site plan applications.