The more I learn about energy efficient houses, the more I realise it's basically all about moisture management. The more energy efficient a house is, the more

The more I learn about energy efficient houses, the more I realise it's basically all about moisture management. The more energy efficient a house is, the more you have to worry about moisture. The biggest problems come when people do things that seem sensible - like insulating, or sealing up walls with render - and don't take into account the never ending stream of water vapour coming from within. Do it wrong and you get black mould and rotten timbers. It's obviously worth doing right - because we expend such a vast amount of energy on heating homes. But every aspect needs careful consideration.