I recently came across a book in the Auckland library system called ‘ Earthships in Europe’ . This is the second edition which came out in 2012 and reviews several earthships built in the UK, France and Spain to see whether the buildings are living up to Mike Reynolds claims that that the design can adapt successfully to any climate across the planet. There is lots of interesting reading here but the conclusions are weak as none of the residential European earthship examples featured in the book have been consistently monitored. What data there is, for example for the Brighton earthship, points to significant shortcomings with thermal performance, although with the caveat that there has not been anyone living in the building as it is a visitor centre. The internal temperatures fell below comfort levels in autumn and winter and they also suffered from high humidity levels and some overheating in summer. The book ends with design recommendations to improve the thermal performance of earthships in temperate climates. These include having greater attention to air tightness, having a mechanical ventilation system to reduce heat loss through ventilation in the winter and improve indoor air quality, considering removing the internal greywater planters to avoid excess humidity and dampness, and having an auxillary heating system. Interesting reading.