Tallaght Apartment Blocks
Thermal Survey
PROJECT OVERVIEW
AltiGeo was appointed to carry out a thermal survey of 4 apartment blocks in Tallaght. The purpose of the survey was to identify significant temperature variations across the external building fabric that could indicate potential cold bridging, heat loss, gaps in insulation continuity or other areas requiring further investigation.
Thermal imaging provides a non-invasive method of reviewing building performance by detecting surface temperature differences that may not be visible during a standard visual inspection.
Survey Methodology
The thermal survey was carried out using a DJI Mavic 3T thermal drone, which allowed AltiGeo to capture thermal imagery of the apartment blocks from suitable aerial positions. The drone-mounted thermal camera was used to review the external building fabric and identify areas showing notable temperature variation.
Thermal cameras detect infrared radiation emitted by objects and convert this information into visible imagery using artificial colour palettes. For this survey, the Hot Iron palette was used to clearly represent variations in surface temperature.
The survey was comenced at approximately 21:30, following sunset at 18:30. External temperatures were recorded at approximately 6–7°C, while internal temperatures ranged between 15–22°C, providing the required temperature differential across the building fabric. The building surfaces were dry, there was no precipitation, cloud cover was approximately 20%, and wind speed was recorded at approximately 9 mph.
Pre-survey conditions were reviewed prior to the inspection. The relevant surfaces were free from direct sunlight for at least one hour, the required temperature difference of 10°C or greater was achieved, and the building fabric was dry and free from precipitation before and during the survey. These conditions allowed the thermal inspection to be carried out in a controlled and suitable manner.
Thermal Imaging Conditions
For a thermal survey to be effective, the following conditions should be achieved before the inspection:
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Heated building – There should be a minimum temperature difference of 10°C between the inside and outside of the building. If the building does not have an operational heating system, temporary heaters may be required to create suitable survey conditions.
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Dry surfaces – External building surfaces need to be dry. The survey should not be carried out during rainfall or directly after a rainy day, as wet surfaces can affect the accuracy of thermal readings.
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Low wind speed – A wind speed of 18 km/h or lower is preferred, particularly for drone-based thermal capture. Lower wind speeds help maintain flight stability and allow images to be captured with accurate overlap, supporting reliable image alignment and survey outputs.
The survey focused on identifying areas of unusual heat loss or temperature variation across the external envelope. Thermal anomalies can indicate potential issues such as cold bridging, insulation discontinuity, air leakage or heat transfer through specific building elements. Any irregularities identified through thermal imagery should be treated as indicative and reviewed further as part of a wider building assessment.
Deliverables
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Drone-based thermal imagery captured using a DJI Mavic 3T
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Visual reference images where required
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Identification of significant temperature variations
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Thermal survey report using the Hot Iron palette
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Record of potential cold bridges or insulation continuity concerns
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Non-invasive building fabric assessment for further investigation