In the case of large and complex buildings, it may be impractical for the thermographic survey and airtightness testing to cover 100% of the building. Where a complete thermographic survey or airtightness testing is deemed impractical by a Suitably Qualified Professional (thermographic survey or airtightness testing), the following guidance applies:
- Airtightness testing: Guidance in airtightness standard TSL2 (or relevant local standard) should be followed regarding the extent of the survey and testing. This could include, for example, airports, large hospitals, high-rise buildings.
- Thermographic survey: Any building with a floor area less that 2000m2 should have a full survey unless it contains a large number of similar rooms, e.g. a health centre or hotel. Any building with a floor area greater that 2000m2 may be sampled by taking images of a representative sample of spaces on each floor including spaces with different activities and at different locations on the floor plan. Each elevation and each elevational and roof treatment/type need to be sampled. Sampling should be increased if evidence of poor building fabric thermal performance is identified from sampling.
23/11/2020 amended text to improve clarity: In the case of large and complex buildings, it may be impractical for the thermographic survey and airtightness testing to cover 100% of the building. Where a complete thermographic survey is deemed impractical by a Level 2 qualified thermographic surveyor, the guidance in airtightness standard TSL2 (or relevant local standard) should be followed on the extent of the survey and testing. This could include, for example, airports, large hospitals, high-rise buildings.
