When You Need a Topographical Survey in Barnet
A topographical survey is required for:
- Planning permission: most cases, especially beyond minor works
- New builds and replacement dwellings: accurate site data for design
- Significant extensions: levels affect drainage and access on sloping or irregular sites
- Conservation areas or heritage assets: detailed site record required
- Sites with trees: BS5837 arboricultural surveys require accurate topographical data
- Drainage and engineering design: invert levels and contours for SuDS compliance
- Setting-out and construction: OS grid coordinates for precise positioning
Most property owners spend £800–£6,500 depending on complexity.
Costs in Barnet/London (2025)
| Site Size | Typical Price (ex VAT) | | --- | --- | | Small residential plot (up to 0.25 acre) | £350–£600 | | Medium site (0.25–1 acre) | £600–£1,200 | | Large/complex site (1–5 acres) | £1,200–£2,500+ | | 0.5 hectares (rough guide) | ~£1,000 |
Prices vary by site complexity, contour interval, and detail requirements.
Deliverables
A topographical survey provides:
- Building footprints with threshold, eaves, and ridge levels
- Boundaries: fences, walls, kerbs
- Trees: trunk diameter, canopy spread, height (critical for TPOs and BS5837)
- Spot levels and contours (0.5m or 1m intervals)
- Drainage covers and visible utilities
- Street furniture and access points
- Formats: AutoCAD DWG, PDF, Revit (BIM) — georeferenced to OS National Grid
Turnaround Time
| Survey Type | Turnaround | | --- | --- | | Topographical survey | Site visit + 1–4 days office processing | | Complex or large sites | 10–20 working days | | Expedited service | Available on request |
Barnet EN4/EN5 Coverage
We provide topographical surveys throughout the London Borough of Barnet — including EN4 (New Barnet, East Barnet, Barnet Gate), EN5 (High Barnet, Chipping Barnet, Arkley), and all surrounding postcode areas: Finchley, Hendon, Edgware, Mill Hill, Friern Barnet, Totteridge, Whetstone, Woodside Park, Colindale, and all N, NW, and EN postcodes.
Local Barnet surveyors include Peter Miko Surveys (07541 498 105) and CADMap Ltd.
Frequently Asked Questions
Q: When do I need a topographical survey in Barnet?
You need a topographical survey for most planning applications in Barnet, especially new builds, replacement dwellings, significant extensions, and sites with trees or complex topography. Barnet's planning authority typically requires accurate site data including contours, boundaries, and tree positions.
Q: What contour interval do I need?
1m contours are standard for planning applications. Drainage and earthworks design typically require 0.5m contours. Confirm with your design team.
Q: What accuracy can I expect?
RICS standards require ±50mm accuracy for detail points. All surveys are georeferenced to OS National Grid with OD heights.
Q: How long does a topographical survey take?
Site visit is typically 1 day for small to medium sites. Drawing production takes 1–4 working days. Large or complex sites may take 10–20 working days.
Q: Do I need a topographical survey for a basement in Barnet?
Yes — Barnet requires Basement Impact Assessments for basement developments, which typically require a topographical survey as part of the documentation.