Measuring the heat transfer coefficient (HTC) in buildings: A stakeholder's survey

The heat transfer coefficient (HTC) is a very important factor influencing the energy performance of a building. Recent studies have shown the importance of on-site measurements of the HTC in reducing the performance gap in buildings. However, its measurement setup and calculation procedures are known to be intense and complex. Due to this, many stakeholders in the building industry find it impractical and insufficient for their needs. This paper presents the results of an international survey that targets such stakeholders with the aim to get their perspectives on HTC measurements on-site. Several stakeholders from 14 countries in Europe participated in the survey. The survey is categorized into four parts: a) basic data about the participants, b) their interest in methods for measured energy performance, c) their views on the characteristics of such a methodology and d) their concerns and opportunities. The results reveal that the stakeholders are highly interested in measuring the HTC on-site. The results also provide interesting insights on the aspects relevant for them and their customers. In particular, we elaborate on their perspective on the time to conduct the measurement, the cost of the setup, the measurement duration and the acceptable error. The assimilated understanding from the survey will help the building and the construction industry to identify opportunities for a progressive assessment campaign involving on-site measurements. This study is part of the International Energy Agency's Energy in Buildings and Communities Programme (IEA EBC) Annex-71 project titled ‘Building energy performance assessment based on optimized in-situ measurements’. •Survey on HTC measurements involving 13 types of stakeholders from 14 countries.•Their perspectives on duration, cost and accuracy of the HTC test are presented.•Their perspectives on the concerns and further opportunities are discussed.•Their preferences are compared with existing HTC measurement methods.•All stakeholders are highly interested in measuring the HTC on-site.