Understanding Historic Buildings

Clarifying the relationship between HEAG099 and HEAG317

• Understanding Historic Buildings: A Guide to Good Recording Practice (HEAG099)
• Geospatial Survey Specifications for Cultural Heritage (HEAG317)

Purpose of this note

Historic England publishes/maintains two important pieces of guidance relating to the recording and documentation of historic buildings.

• HEAG099 provides guidance on approaches to understanding historic buildings, including descriptive recording and analytical interpretation, and guidance on the different levels of recording.
• HEAG317 provides the technical specification for metric geospatial survey of cultural heritage assets, including measured building surveys, laser scanning, photogrammetry, and the production of accurate spatial datasets.

While both documents support the recording and conservation of historic buildings, they serve distinct but complementary purposes.

This note clarifies when to use each guidance document.

Key distinction

HEAG099 focuses on interpretative building recording.

This may include:

• Written descriptions
• Photographic documentation
• Analytical interpretation of fabric
• Phasing analysis
• Drawings that support understanding of development and significance

However, these activities do not necessarily require metric survey data.

HEAG317 focuses on metric geospatial survey.

This includes:

• Measured building surveys
• 3D laser scanning
• Photogrammetry
• Accurate 2D and 3D spatial datasets
• Survey control networks
• Digital terrain models
• Monitoring and deformation analysis

These surveys provide precise spatial data suitable for conservation planning, repair design, monitoring and long-term asset management.

When HEAG317 should be referenced

Projects involving historic buildings should reference HEAG317 where accurate spatial data is required, including, for example:

• Preparation of conservation or repair drawings/schedules
• Structural assessment and monitoring
• Building information modelling (HBIM)
• Long-term digital archiving
• Any archaeological or architectural analysis/investigation requiring accurate metric data

In such circumstances, geospatial surveys should conform to the technical requirements set out in HEAG317.

Complementary use of both guidance documents

In many projects, both guidance documents may be used together.

For example:

• HEAG317 may provide the metric spatial framework
• HEAG099 may guide the interpretation and analytical recording of historic fabric

Together, they support a more comprehensive understanding and documentation of historic buildings.

This clarification was issued on 20 March 2026.