The Houses can sense those with the aptitude or the innate ability, and will slowly guide them there subconsciously. They would be allowed to enter, but only when the Magiq felt it would be right, or in times of great need.
Gossmere would function like a shelter in most Sleeper’s eyes, but to those who ahve the capacity to be awoken, they would notice some differences. Same with most other houses. If they are lead there, or happen upon thephyisical place it’s tethered to, they could probably see a glimmer of what it truly looks like, instead of the version that sleepers (or mundies) could see.
Those with the ability and the connection to a guild, would invariably end up at the house itself.
I agree with Victorian. pretty much they see the guild and then gain the chioce of stepping into this mad world we call home.