A door in a dream usually represents a choice standing in front of you -- an opportunity you can step through, or a transition you're still deciding whether to make. A locked or unreachable door can reflect an option that feels closed off, while an open one often signals readiness.
In men's nativities, if the part of marriage shall fall in signs obedient; and in women's in signs imperant, the woman shall rule the man, and the man shall obey; sin autem contra, dic contrai. - William Lilly (1602.-1681.)