Our downstairs loo in the new extension will have no external walls and so no window. DH (who is fucking obsessed with ventilation and leaves the bathroom window open all year round) is insisting that it will need an extractor fan. Is he right? Nobody apart from the builder does particularly rank poos, and I can't see why it would develop a damp problem. Would building regs require an extractor? How would it vent anyway? I hate extractor fans. I grudgingly admit that we will need one in the shower room, but that's it right?