11 CATHEDRAL COMMUNICATIONS THE BUILDING CONSERVATION DIRECTORY 2025 PROFESSIONAL SERVICES 1 GEOSPATIAL SURVEYS Why getting it right matters ANDY BEARDSLEY The new document also supersedes Historic England’s 3D Laser Scanning for Heritage 2018 guide, as technological advancements and the increasing integration of geospatial surveys into heritage conservation since 2018 mean that the guide is now outdated. Another Historic England guide, Understanding Historic Buildings: A Guide to Good Recording Practice remains in use. However, while this 2016 document is useful for historical analysis, it fails to adequately reference the geospatial specifications, leading many conservation professionals to assume that basic recording methods are sufficient for full geospatial survey. This creates a potentially dangerous stumbling block where professionals believe they are using data that complies with best practice when, in fact, they are working with incomplete or inaccurate survey data. The two documents serve very different purposes. WHEN TO USE THEM Historic England’s Geospatial Survey Specifications The table overleaf lists some of the many applications for accurate and detailed geospatial survey data. However, there is no explicit directive detailing when a geospatial survey must be undertaken, apart from the requirement for recording where a A 3D geospatial survey of St Mary Abchurch, one of Wren’s city of London churches: 3D laser scanning captures the detailed information required for draughting CAD drawings (All images: Terra Measurement Limited) CROSS THE heritage sector, two critical issues are quietly undermining conservation efforts: the rise of easily accessible but poorly controlled 3D survey data, and the neglect of commissioning best practice geospatial surveys for building conservation projects. Many heritage professionals, estate owners and developers misunderstand the role and need for 3D geospatial surveys. Decision makers often procure or approve services based on cost rather than capability, unaware that incorrect data can set projects back years. The ill-informed decisions that follow lead to poor cost analysis, the misalignment of new work and compromised monitoring strategies. The result is wasted funds and risks irreversible damage to heritage assets. So how do we fix this? By understanding what makes a geospatial survey reliable, commissioning the right expertise, and, above all, adhering to Geospatial Survey Specifications for Cultural Heritage 2024—a specification framework published by Historic England that is equally relevant in all corners of the UK. Historic England’s guidance is now well established as the go-to standard for 3D geospatial surveys. The processes it outlines are essential for ensuring that the detailed information required for draughting CAD drawings and building 3D models is captured correctly. The guidance provides a benchmark for accuracy and consistency in geospatial data collection and ensures that surveys are both technically sound and practically useful. There is no accurate alternative: all previous methods are obsolete for anything other than sketch drawings. Despite its critical importance, , yet it is too often overlooked. In this article I hope to demonstrate that a 3D geospatial survey undertaken with the appropriate controls benefits the building and the design team in many ways, potentially for decades ahead. A brief glossary of technical terms is included at the end. THE EVOLUTION OF HISTORIC ENGLAND’S GEOSPATIAL SURVEY SPECIFICATIONS Originally developed as the Metric Survey Specifications for Cultural Heritage (English Heritage, 2009), Geospatial Survey Specifications for Cultural Heritage has been refined over many years of practice and research, and the core principles have remained consistent.
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