Is there any problem I don't know about with doing that? e.g. less safe, insurers don't like them, etc, etc?
Also, a lot of the small windows have locks on, when I can't see that opening that window would actually do you much good. Do these really need locks on? Do burglars have cunning ways of getting through small windows?
I can imagine I may need to talk to the insurers, but I don't think we specified whether we have locks or not at the moment.