What's the relative pay-off between running a dehumidifier vs. opening the windows? I confess I'm a serial window opener and something of a fan of drafts, and we've never bothered with a tumble drier (we used to have one, but I think we used it once in six years). We dry clothes inside but I leave the windows on the latch. I'm a bit more conscious of it now, as this is a detached sixties (groovy) house with huge six foot windows, but also with double-glazing, loft insulation, cavity walls, and general hermetic sealing that was probably unanticipated by the original builder. I'm minded that houses should breath, but I'm also mindful that I'm heating the outside world and getting no thanks for raising the neighbourhood's temperature. That said, the bathroom does need a big extractor fan, the combination of two external walls and one of those giant windows condenses out about gallon of water, especially as I like my showers and baths to be the temperature of magma.