You might have benefited from MVHR, dMVHR, or an EAHP: * MVHR extracts air from "warm" rooms like kitchens and bathrooms, runs it through a heat exchanger to w

You might have benefited from MVHR, dMVHR, or an EAHP: * MVHR extracts air from "warm" rooms like kitchens and bathrooms, runs it through a heat exchanger to warm new supply air, and then pushes the supplied air into other rooms in the house. It stands for Mechanical Ventilation with Heat Recovery. These systems can significantly increase the efficiency and comfort of your house, provided you also air tighten. * dMVHR is similar, supplying fresh air but reclaiming heat, except the "d" is for distributed. They're like extractor fans but they don't waste the lovely heat. * EAHP is an Exhaust Air Heat Pump. Usually they sit on top of an invented (eg pressurised) hot water cylinder, and they'll take hot, humid air out of whatever rooms you duct them to, heat you water for a quarter of the cost of an immersion heater, then blow cold air out of your house. This is a great option IMO (I have one) but unlike the first two options it depressurises your house and draws cold air in from outside through drafty bits of your house unless you have a corresponding system to warm incoming air at a similar rate to it being expelled. tl;dr there are options to recover the heat while expelling the moisture!