Type: Case study

Paynes Lane fire training facility: digital surveying to support brownfield earthworks

Date: 02 July 2026

Warwickshire County Council commissioned the development of a new fire training facility on a former railway siding and storage yard.

Paynes Lane fire training facility: digital surveying to support brownfield earthworks — Paynes Lane fire training facility. Image credit: Tregartha Civil Engineering.

The brownfield site presented typical legacy issues: variable ground conditions, uneven terrain and a high likelihood of buried obstructions associated with historic industrial use.

To create a level construction platform, the project required significant remediation and earthworks, including cut and fill operations and the movement of imported and exported materials.

Engineering challenges

The project team needed to address several constraints common to brownfield redevelopment:

Accurately quantifying cut and fill volumes across a complex site
Identifying and managing buried obstructions from historic railway use
Coordinating earthworks within a confined working area
Maintaining reliable site information as ground levels changed rapidly
Mapping existing infrastructure to support construction sequencing

These challenges made traditional surveying alone insufficient for the level of accuracy and frequency required.

Digital surveying approach

To support planning and ongoing decision making, the team adopted a digital-first approach.

Aerial drone surveying, combined with advanced modelling software, was used to provide accurate and up-to-date site intelligence throughout the project.

Project progress with design overlay. Image credit: Tregartha Civil Engineering.

A pre construction drone survey established a baseline topographical model.

Weekly drone flights were then undertaken throughout the earthworks phase, allowing the team to monitor changes and adjust plans in near real time.

Key technical outputs

3D topographical modelling: digital terrain models provided detailed insight into existing levels and ongoing changes.

Site volume analysis. Image credit: Tregartha Civil Engineering.
Isopach mapping: cut and fill drawings and volume calculations supported material management and sequencing.
2D photogrammetry: high resolution imagery captured site conditions and helped map existing infrastructure.

Drone survey with existing infrastructure showing critical asset easements. Image credit: Tregartha Civil Engineering.
Integrated data analysis: historic records were combined with survey outputs to identify potential obstructions early.

Drone overlay with historic records to trace hidden obstructions. Image credit: Tregartha Civil Engineering.
Progress monitoring: regular visual updates improved coordination between the client, contractor and design team.

Outcomes

The combined use of traditional surveying and drone based data capture gave the project team a clear understanding of site conditions throughout the works.

According to the project report, uncharted obstructions and existing infrastructure were identified and managed more effectively.

This approach supported:

More predictable earthworks operations
Reduced disruption from unexpected buried features
Improved material management through accurate volumetric analysis
Better communication between stakeholders through shared visual data

The digital workflow enabled the team to move from reactive problem solving to proactive planning, which is increasingly important in brownfield redevelopment.

Completed project — The completed project. Image credit: Tregartha Civil Engineering.

Lessons learned

Frequent digital surveys reduce uncertainty on sites where ground conditions change rapidly.
Integrating historic records with modern survey data helps anticipate buried obstructions.
Visual communication tools improve coordination between multidisciplinary teams.
Drone based volumetrics can support more efficient material movement planning, especially on constrained sites.