Our Services

Topographic survey.
RICS-regulated. UK-wide.

Measured land surveys to engineering tolerance — levels, contours, boundaries, utilities and surface features captured to OSGB36, delivered as CAD, DTM and BIM-ready outputs. From single-plot residential through to multi-kilometre infrastructure corridors.

±15mm
Standard positional accuracy
5–14d
Typical turnaround
OSGB36
National datum referenced
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What it is

What is a topographic survey?

A topographic survey is a measured land survey that records the precise position, elevation and physical features of a site. It captures hard detail (buildings, kerbs, walls, manholes, lamp columns), soft detail (trees, vegetation, water), ground levels and contours, and underground utility evidence visible at surface level — all referenced to OSGB36 national datum or a defined local grid.

The deliverable is a survey-grade CAD drawing and 3D digital terrain model that becomes the existing-site base for architects, civil engineers, BIM coordinators and planning applications. It is the single most important measured input to any new build, extension, infrastructure scheme or land development.

Angell Surveys delivers topographic surveys across the UK under a documented RICS-standard quality framework — with independent check points, traceable control and full accuracy reporting issued with every survey.

Deliverables

What you receive.

Every topographic survey ships with full QA documentation and a fixed deliverable set. Optional outputs available on request.

2D CAD Drawing (DWG)

Survey-grade AutoCAD DWG showing all hard and soft detail, ground levels, contours and boundaries. Layered to RICS conventions and ready for architect/engineer overlay.

3D Digital Terrain Model

DTM/DSM with contours at 0.25 m or 0.50 m intervals, plus break-lines and spot heights. Suitable for civils setting-out, drainage design and earthworks calculation.

OSGB36 Control & QA Report

Full control network with primary station coordinates, GNSS observation log, independent check point residuals and final accuracy statement. Audit-traceable.

Point Cloud (Optional)

LAS/LAZ classified point cloud from UAV photogrammetry or terrestrial laser scanning where the site benefits from dense 3D capture (heritage, complex terrain, vegetation).

Orthomosaic Imagery (Optional)

Sub-5cm true orthophoto draped over the survey for visual context, planning illustration and feature verification. Delivered as GeoTIFF.

LandXML & BIM (Optional)

LandXML surfaces for direct import into Civil 3D, MX and OpenRoads. Revit/IFC topo families for BIM coordination on building-led projects.

Accuracy, Control & Datum

Surveyed to engineering tolerance, traceable to national datum.

Every topographic survey we issue is referenced to OSGB36 horizontally (via the OSTN15 transformation from GNSS-observed ETRS89) and ODN vertically (via the OSGM15 geoid). Control is established by primary GNSS network and total-station traverse, with independent check points reported alongside every deliverable.

Tier Hard Detail Ground Levels Primary Method Typical Use
Engineering ±5 mm ±10 mm Total-station traverse with check rays Rail, highway setting-out, structural verification, tunnel and bridge alignment
Standard ±15 mm ±25 mm GNSS+TS hybrid or static GNSS with PPK Most commercial development, planning applications, civils design base
UAV Photogrammetry ±25–30 mm ±30–50 mm UAV photogrammetry with documented GCP network Large open sites, brownfield, solar farms, earthworks monitoring, corridor mapping
UAV LiDAR ±20 mm ±25 mm UAV LiDAR with classification Vegetated terrain, woodland, complex surface texture, ground-under-canopy

Independent check points are observed and reported with every survey. Residuals against control are issued as a stand-alone accuracy report referencing the methodology, equipment, observation times and personnel — audit-traceable to the RICS Surveys of Land, Buildings and Utilities professional statement.

Who It's For

Built for the way you'll use it.

Topographic surveys delivered to the data structure each discipline expects — no rework, no remapping.

A

Architects & Designers

RICS-layered AutoCAD DWG with hard detail, soft detail, levels and boundaries on separate layers. Ready to overlay a proposed scheme on day one of design.

B

Civil & Highways Engineers

LandXML surfaces, contour break-lines and 3D DTM imported direct into Civil 3D, MX or OpenRoads. Drainage and earthworks setup with no recoding.

C

Planning & Development

Existing-site base drawings to support full planning applications. Boundary, levels, tree positions and surface features captured to RICS standard.

D

Infrastructure & BIM

Engineering-tolerance topographic data for rail, highways, utilities and nuclear corridors. Revit/IFC topo families for BIM coordination on building-led projects.

Our Process

How we work.

A documented, quality-assured workflow from initial brief to final deliverable.

01

Brief & Fixed Quote

Send a site location, boundary and scope summary. We respond within 24 hours with a proposal covering deliverables, accuracy specification and lead time.

02

Control & Capture

Primary GNSS control established to OSGB36. Site captured by total-station traverse, UAV photogrammetry or hybrid LiDAR depending on size, complexity and vegetation cover.

03

Processing & QA

Data processed in-house. Independent check points validated against the control network. Drawing produced to RICS layering convention with full attribute coding.

04

Delivery

DWG, DTM, PDF and accuracy report issued within 5–14 working days of capture depending on site size. Files referenced to OSGB36 and ODN unless local grid specified.

Sector Applications
Residential Development Commercial Development Highways & Roads Rail Infrastructure Utilities & Water Renewables & Solar Heritage & Listed Buildings
Topographic vs Measured Building Survey

When do you need which?

The two surveys are complementary. A topographic survey describes the land; a measured building survey describes the building. Most development projects with an existing structure on site need both.

  Topographic Survey Measured Building Survey
What it capturesExternal site: levels, contours, boundaries, hardstanding, vegetation, surface utility evidenceBuilding geometry: floor plans, sections, elevations, ceiling heights, openings, finishes
Output2D site plan + 3D DTM/DSM2D floor plans + sections + elevations, optional 3D BIM model
Primary usePlanning, civils design, drainage, earthworks, landscape designRefurbishment, retrofit, change of use, heritage, scan-to-BIM
DatumOSGB36 / ODNLocal building grid (often referenced to OSGB36 for context)
Typical methodGNSS+TS, UAV photogrammetry, UAV LiDARTerrestrial laser scanning (TLS) + total station + handheld scanner
RICS standardSurveys of Land, Buildings and UtilitiesSurveys of Land, Buildings and Utilities
FAQ

Topographic survey questions.

The questions clients ask us most frequently before instructing a topographic survey.

What is a topographic survey?
A topographic survey is a measured land survey that records the position, elevation and features of a site — including levels, contours, boundaries, buildings, utilities, trees and hardstanding. The output is a CAD drawing or DTM referenced to OSGB36 national datum (or a local site grid where required), used as the base information for architects, civil engineers and planning applications.
What accuracy do you survey to?
Standard topographic surveys are delivered to ±15 mm absolute positional accuracy on hard detail and ±25 mm on ground levels, referenced to OSGB36 / ODN via static GNSS or PPK. Engineering-tolerance surveys (railway, highway, structural setting-out) are delivered to ±5 mm where required, using total-station traverse and independent check points.
How long does a topographic survey take?
A standard residential or small commercial topographic survey is typically captured in one day with deliverables issued within 5–7 working days. Larger sites take 2–5 days on site with 7–14 working days for processing. UAV photogrammetry combined with GCP control can cut site time on larger areas significantly. Urgent turnarounds are available on request.
Do I need a topographic survey for planning permission?
Yes — most local planning authorities require an accurate topographic survey as part of a planning application, particularly for new builds, extensions over 1 storey, sloping sites, and any development affecting trees, boundaries or drainage. The survey forms the existing-site base drawing that the architect overlays the proposed scheme onto.
What deliverables do you provide?
Standard outputs are an AutoCAD DWG (2D plan with levels and contours), a 3D DTM/DSM, an accuracy report and a PDF. Optional deliverables include LandXML for civils setup, point clouds (LAS/LAZ), orthomosaic imagery, Revit/IFC models, and BIM-ready files. All deliverables are referenced to OSGB36/ODN unless a local grid is specified.
Are you RICS regulated?
Yes. Angell Surveys is regulated by the Royal Institution of Chartered Surveyors (RICS). All measured survey work follows the RICS Surveys of Land, Buildings and Utilities professional standard, with documented control networks, independent check points and full QA records issued with every deliverable. Our public RICS Firms profile is at ricsfirms.com/office/681790/Angell-Surveys-Ltd.
Do you cover the whole of the UK?
Yes — we deliver topographic surveys across England, Wales, Scotland and Northern Ireland. Our work covers everything from single-plot residential surveys through to multi-kilometre infrastructure corridors for rail, highways, utilities and nuclear clients.
What is the difference between a topographic survey and a measured building survey?
A topographic survey records the external site — levels, contours, boundaries, hardstanding, vegetation and surface features — and produces the existing-ground base drawing for development. A measured building survey records the internal and external geometry of an existing building — floor plans, sections, elevations, ceiling heights, window and door openings — and produces the as-built drawings used for refurbishment, conversion or BIM modelling. The two surveys are complementary: a development project will often need both, with the topographic survey supplying the external base and the measured building survey supplying the building geometry.
What datum is a UK topographic survey referenced to?
Horizontal positions are referenced to OSGB36 (Ordnance Survey National Grid) via the OSTN15 transformation from GNSS-observed ETRS89 coordinates. Vertical positions are referenced to ODN (Ordnance Datum Newlyn) via the OSGM15 geoid model. A site-specific local grid can be substituted where the project specification requires it — common on rail (Snake grid) and on phased developments where a contractor-defined site grid is in use.
Can UAV (drone) data replace a ground-based topographic survey?
On open, low-vegetation sites yes — UAV photogrammetry with a documented GCP network and independent check points routinely achieves ±10–25 mm absolute accuracy on hard detail at 1σ (RICS Band D or E). On sites with dense vegetation, narrow access corridors or where engineering tolerance is critical, UAV is combined with terrestrial GNSS or total-station capture, or LiDAR is used in place of photogrammetry. We pick the methodology to match the accuracy specification — never the other way around.
What CAD layering convention do you use?
All AutoCAD DWG deliverables follow the RICS Surveys of Land, Buildings and Utilities professional statement layering convention, with separate layers for hard detail, soft detail, levels, contours, boundaries, utilities (visible evidence) and survey control. Layers are colour-coded and named to import cleanly into Revit, Civil 3D, MX, OpenRoads and ArchiCAD. A layer schedule is issued with every drawing.
Related Services
Service
Aerial Survey
UAV photogrammetry for larger sites, corridors and brownfield — orthomosaic, DSM/DTM and volumetric outputs at sub-5cm accuracy.
Learn more →
Service
LiDAR & Laser Scanning
Engineering-grade point cloud capture for vegetated terrain, dense urban sites and structural assets where photogrammetry alone cannot deliver.
Learn more →
Service
Measured Building Survey
RICS-standard floor plans, sections and elevations of existing buildings for refurbishment, planning and BIM coordination.
Learn more →
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Topographic survey, scoped and quoted within 24 hours.

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