My landlord replaced the windows in my place a couple of years ago. All of them are fine except the two in my bedroom, which are leaking copious amounts of cold air. I asked him to come and look at them during the recent cold snap and he downplayed the problem. Is this something I can have repaired myself and deduct from the rent? I think the windows are either defective or were improperly installed - the rest of them are fine. Thanks for your help.