mechanical ventilation with heat recovery
This seems a very much needed thing. Whilst our house we live in is a shambles and moving it on a pipe dream. But the holiday let we run is finished to very different standards. I put an air quality monitor in there and the results were eye opening. On a dreich day 6 adult guests and a dog would lock themselves away and batten down and the CO2 levels would rise stupendously.
I guess it’s not surprising – a modern airtight box rather than our draughty old house with 7 sets of lungs is going to do that. I don’t think too many houses in the UK have got them fitted yet, but it needs to be a thing if we are going to build houses to these better standards.