Preserving Ecclesiastical Heritage: The Case for Best Practice Geospatial Surveys

By Andy Beardsley , Founder and Managing Director, Terra Measurement Limited

A Legacy Worth Preserving

Churches are more than places of worship—they are historical landmarks, community hubs, and treasures of architectural heritage. Whether it’s a modest village chapel or a grand cathedral, these buildings embody centuries of history, craftsmanship, and cultural identity. Yet, caring for these historic places has become increasingly complex.

Ecclesiastical buildings face challenges ranging from environmental stress to funding limitations. Many are aging, with cracks forming, materials weathering, and structural movements occurring over time. The key to preserving them is good advice and the right tools to ensure informed decisions are made about their maintenance, repair, and conservation.

This principle was at the heart of the Wren300 Conservation Project, part of the Wren300 Festival in 2023, which celebrated the 300th anniversary of Sir Christopher Wren’s death. Together with Cliveden Conservation, my team at Terra Measurement explored how advanced geospatial surveys could address the challenges of conserving these architectural treasures.

Our collaboration resulted in the creation of the ‘3D Geospatial Surveys and Digital Technology for Historic Places of Worship’ Toolkit, a practical guide designed to empower church guardians, volunteers, and community groups with the knowledge they need to care for their buildings into the future.

The W300 Toolkit was developed to bridge the gap between cutting-edge technology and the practical needs of those who care for historic places of worship. It’s designed to demystify geospatial surveys and provide clear, actionable advice for church incumbents, fabric committees, and community groups.

Why 3D Geospatial Surveys Matter

Traditional methods for inspecting and documenting historic churches, such as visual assessments or manual 2D surveys, can only go so far. While they provide some level of detail, they often fail to capture the true complexity of these buildings. This can lead to incomplete data, misinformed repairs, and, ultimately, higher costs.

In contrast, 3D geospatial surveys offer a new way forward. By leveraging advanced technologies—laser scanning, photogrammetry, and drone-mounted cameras—these surveys create highly accurate, detailed digital records of ecclesiastical buildings.

Disaster Recovery: In the event of fire, flood, or other catastrophic damage, accurate 3D data becomes invaluable for reconstruction. The Notre Dame restoration highlighted the importance of pre-existing geospatial surveys, and the same principle applies to ecclesiastical buildings.

Here’s why they matter:

1. Unprecedented Accuracy: Laser scanning captures millions of data points to create precise 3D models, accurate to the millimetre. During Wren300, for example, we documented the bell tower of St Mary Abchurch, capturing every detail of its structure and ornamentation.
2. Long-Term Value: A 3D geospatial survey is not just a snapshot; it’s a permanent digital record that can be used for monitoring, planning, and disaster recovery. As highlighted in the Innovations in Geospatial Surveying for Heritage Conservation, having high-quality baseline data ensures that conservation efforts are both sustainable and efficient.
3. Non-Invasive and Safe: Geospatial surveys are ideal for fragile historic environments. Techniques like SLAM scanning allowed us to explore and document the charnel house beneath St Mary Abchurch—an inaccessible crypt storing human remains—without disrupting the space.
4. Disaster Recovery: In the event of fire, flood, or other catastrophic damage, accurate 3D data becomes invaluable for reconstruction. The Notre Dame restoration highlighted the importance of pre-existing geospatial surveys, and the same principle applies to ecclesiastical buildings.

The Toolkit: A Guide for Guardians

The W300 Toolkit was developed to bridge the gap between cutting-edge technology and the practical needs of those who care for historic places of worship. It’s designed to demystify geospatial surveys and provide clear, actionable advice for church incumbents, fabric committees, and community groups.

Key Highlights from the Toolkit

1. Understanding 3D Geospatial Surveys: The toolkit explains the fundamentals: What is a 3D survey? How do technologies like terrestrial laser scanning, photogrammetry, and drones work? When are these techniques most appropriate?
2. Real-World Applications: During Wren300, geospatial surveys revealed critical insights: The north wall of St Bride’s Church was documented using photogrammetry to capture years of environmental damage, aiding Cliveden Conservation’s repair planning. Drone-mounted photogrammetry was used to survey the high spire of St Mary Abchurch, offering detailed views without the need for scaffolding.
3. Best Practices: The guide aligns with Historic England’s Geospatial Survey Specifications for Cultural Heritage, emphasising: The importance of survey control for accuracy and consistency. Adherence to industry standards to ensure data quality and compatibility.
4. Empowering Communities: It’s not just for professionals. The toolkit provides practical advice for volunteers and community groups, helping them understand what to expect from a survey and how to commission one effectively.

Lessons from Wren300: The Power of Collaboration

The Wren300 Square Mile Churches Conservation Project showed how collaboration between disciplines—surveyors, conservators, and community stakeholders—can elevate heritage care. By bringing together Terra Measurement’s expertise in geospatial surveying and Cliveden Conservation ’s knowledge of historic materials, we created solutions that were both innovative and practical.

One key lesson was the importance of aligning modern technology with traditional craftsmanship. For instance, combining high-resolution digital scans with conservation strategies allowed us to document and protect vulnerable features while respecting the character of these historic buildings.

As one Wren300 participant noted: "The level of detail captured in these surveys is incredible. It opens up new possibilities for understanding and preserving these spaces, not just for today, but for generations to come."

As one Wren300 participant noted: "The level of detail captured in these surveys is incredible. It opens up new possibilities for understanding and preserving these spaces, not just for today, but for generations to come."

Empowering the Future: How You Can Help

Churches are often at the heart of their communities, and their care should involve everyone—from professionals to volunteers. However, without access to the right advice and technology, many guardians struggle to make informed decisions about repairs and conservation.

The W300 Toolkit is a starting point for empowering those responsible for these buildings. By understanding the potential of 3D geospatial surveys, communities can secure the future of their heritage with confidence.

Take Action Today

Whether you’re a church guardian, fabric committee member, or heritage professional, the tools to transform your approach to conservation are here.

?? Download the W300 Toolkit [Click here]. ?? Learn more about Terra Measurement’s work [Click here].

Let’s ensure the legacy of our historic places of worship endures. By combining centuries of tradition with the power of modern technology, we can preserve these spaces for generations to come.

#HeritageConservation #3DSurveying #ChurchPreservation #Wren300 #HistoricEngland

Historic England Churches Conservation Trust The Church of England Catholic Church Friends of Friendless Churches SPAB Icon - The Institute of Conservation The Methodist Church Quakers in Britain National Churches Trust Heritage Network Heritage Lottery Fund The National Lottery Heritage Fund Church Commissioners for England – Real Estate Church of Scotland The Estates of Hyde Park The Church in Wales | Yr Eglwys Yng Nghymru Church Times