Dr. Oliver Kinnane:

Any contemporary builds that include a heat pump should have a mechanical ventilation system, be it a mechanical heat recovery ventilation system or a standard extract ventilation system. That is required. There will be fresh air within the space. Deputy Healy-Rae raises a good point. It is important that we continue to monitor and invest more in monitoring the air quality within buildings as we change our construction types and increase the airtightness and energy efficiency of houses.

The point about thermal comfort is also a good one. It is one of the major issues that carbon emissions related to the built environment have been creeping up for three or four decades because our thermal requirements or needs have increased quite dramatically. A study by the University of Cambridge a few years ago showed that, back in the 1970s, people were happy to live in homes heated to 14°C to 15°C, gather around a heat source in the evening and then retreat into cold bedrooms again, whereas now we heat big volumes of space within our ever-increasingly sized homes up to 22°C or 23°C. That is a major issue.