In order to reduce emissions the UK requires that all new buildings meet emissions targets, as mandated under the EU Energy Performance of Buildings Directive. However, in the drive to decarbonize buildings it is important that sufficient attention is paid to the potential risks from unintended consequences. Two particular concerns are the increased risk of new (more thermally efficient) buildings overheating, and indoor air quality (IAQ) problems associated with reduced ventilation rates.

The combined issues of energy performance and indoor environmental quality are investigated in this project by conducting post-occupancy studies of student accommodation developments to help understand how these buildings are performing in practice. Two case study developments were monitored for 8 months over the 2017-18 academic year. Over 80% of the bedrooms monitored failed all the empirical tests for overheating. This was due to poor ventilation, a lack of solar shading, and high internal gains. Indeed, many participants reported finding their rooms to be “unusable” in warmer weather, which they judged to have negatively impacted on their studies. Meanwhile those bedrooms without continuous mechanical ventilation extract were found to have serious IAQ issues, as they routinely exceeded 3000PPM carbon dioxide overnight.

These findings raise concerns over whether overheating risk is being adequately assessed at the design stage in student accommodation developments. It also has implications for how these residences are likely to perform in the years ahead as the UK climate continues to warm.