Writing a Topographical Survey Specification for a Planning Application

The scenario

A planning consultant is preparing a planning application for a 2-hectare residential development in the south of England. They need a topographical survey of the site to support the planning application. They write a client-facing specification to send to three surveyors for fee quotes.

This article walks through the specification, section by section.

Section 1: Project details

• Site address and postcode
• OS grid reference (Easting, Northing to 6 figures)
• Total site area (hectares)
• Reason for survey: planning application
• LPA (Local Planning Authority) name
• Planning application reference (if known)
• Required survey completion date

Section 2: Required accuracy

• RICS accuracy band: Band B (±50mm at 1:200 scale)
• Spot height accuracy: ±50mm
• Contour accuracy: ±50mm

The accuracy band is determined by the use case. For a planning application, Band B is the standard.

Section 3: Scope of features

• Spot heights on a _____ m grid (5m / 10m / 20m)
• Contours at _____ m interval (0.25m / 0.5m / 1.0m)
• Building outlines + ridge / eaves heights
• Roads, kerbs, footways, paved areas
• Boundary features: walls, fences, hedges, ditches
• Trees: individual canopies (>3m spread) and woodland outlines
• Water features: streams, ponds, ditches
• Manholes, gullies, inspection chambers
• Utility covers, lamp posts, signage
• Service runs (above ground only)
• Other: [SPECIFY]

Section 4: Survey methodology

Primary method: [GNSS RTK / Total station / Drone / Mixed]

Control:

• Local control network with [N] control stations
• Tied to OS National Grid via GNSS RTK with SmartNet / OS Net correction
• Accuracy: sub-2cm horizontal, sub-3cm vertical
• Coordinate system: OSGB36 / OS National Grid
• Datum: Ordnance Datum Newlyn (ODN)

Coverage:

• Total site area: 2 hectares
• Estimated duration on site: 1-2 days

Section 5: Deliverables

5.¹1 2D Plan

5.2 Digital Terrain Model (DTM)

5.3 GIS / BIM integration (optional)

• GeoPackage (.gpkg) for GIS integration
• IFC for BIM coordination

Section 6: Quality assurance

• Independent check shot at 5 random points per hectare
• Traverse closure: target < 1:10,000
• RMSE check on GNSS baseline: target < 20mm horizontal
• Sign-off by MRICS / FRICS surveyor before delivery
• Verification report included

Section 7: Delivery

• Format: DWG (AutoCAD 2018+) + PDF + LandXML
• Method: secure file transfer (no email)
• Turnaround: 10 working days from site access
• Revisions: 1 round of minor revisions included

Section 8: Fee

Payment terms: 50% on instruction, 50% on delivery.

Section 9: Surveyor credentials and insurance

• Professional Indemnity: [GBP X,000,000]
• Public Liability: [GBP X,000,000]
• Firm regulated by: RICS
• Surveyor credentials: MRICS / FRICS membership number
• CAA Permission for Commercial Operation (PfCO) / A2 Certificate of Competence (if using drones)

Section 10: Surveyor certification

"I, [NAME], MRICS / FRICS, of [FIRM NAME], confirm this specification is consistent with RICS Measured Surveys of Land, Buildings and Utilities 3rd edition Section 3.²³"

Signed: ________ Date: ________ RICS Membership Number: [NUMBER]

Download

Next steps

• See our Topographical Survey service page
• See Asset 1: The Complete Guide
• Book a 15-minute clarity call

References

Frequently asked questions

How long does a topographical survey take? A 1-hectare site with mixed vegetation typically takes 1 day on site for a 2-person GNSS team, plus 1-2 days for processing and drafting. Larger or more complex sites take proportionally longer.

What accuracy can I expect from a topographical survey? With modern GNSS RTK and the RICS Measured Surveys 3rd edition methodology, typical accuracies are:

• 15-20mm horizontal, 20-30mm vertical for open-sky GNSS RTK
• 2-5mm for total station work
• 20-50mm for drone photogrammetry (depending on flight height)

Do I need a topographical survey for a small extension? For a typical rear extension, a 5m-grid topographical survey at 0.25m contours is sufficient. For a side extension or a more complex site, a 2m grid may be needed.

How do I choose between GNSS, total station, and drone? Large open sites favour GNSS RTK (fast, cost-effective). Tight urban sites with kerbs and drainage favour total station (no satellite issues). Large external sites favour drone (fast coverage). For most UK 2026 projects, a mixed approach works best.

Can a topographical survey locate underground services? Not by default — that's a separate PAS 128 utility survey. A topographical survey captures only the visible utility covers, manholes, and inspection chambers. For underground service detection, a separate PAS 128 Type B or Type A utility survey is required.

What is the difference between a topographical survey and a land survey? They are essentially the same thing. "Land survey" is the older term; "topographical survey" is the modern RICS-preferred term. Both produce the same deliverable: a 2D plan with contours, spot heights, and features.

How do you integrate a topographical survey with the OS National Grid? Modern surveys use GNSS RTK with OS Net correction, applied via the OSTN15 transformation grid to convert ETRS89 satellite coordinates to OSGB36 local grid coordinates. The output is fully OS-compatible.

Can a topographical survey be done in winter? Yes, but with caveats. Frozen ground affects spot height accuracy. Snow cover obscures ground features. Heavy rain makes site access difficult. Most UK 2026 surveys are done in spring, summer, or early autumn.

How do I commission a topographical survey? The standard process: send a brief, receive a fixed-fee quote, verify surveyor credentials, arrange site access, site visit, CAD/DTM production, QA check, delivery. Most 2026 quotes are returned within 48 hours.

How to commission

Book a 15-minute clarity call with an Icelabz topographical surveyor. We'll review your situation and give you a fixed fee in 24 hours. Or read the complete topographical survey guide and see the topographical survey service page for the full service description.