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

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.

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.

  

• 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.

  

• Integrated data analysis: historic records were combined with survey outputs to identify potential obstructions early.

  

• 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.

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.

Project details

• Project: Paynes Lane Fire Training Facility
• Owner: Warwickshire County Council
• Surveying and data: Tregartha Civil Engineering
• Location: Warwickshire, United Kingdom
• Year built: 2024

Image credit: Tregartha Civil Engineering.