And of course, as FC houses are freed in the classic wards, those plots would only become personal housing after the relocation process is completed (to avoid disrupting things too quickly and to prevent FCs from losing their house before they have unlocked their district). In the end, once all FCs that already own a house have obtained their own district, all houses in the classic wards would become personal houses entirely, giving more players the chance to own a home. This way, everyone benefits, whether FCs or solo players.

3) Finally, if the classic wards become overcrowded, implement an automatic system that unlocks new wards to allow more players to own their own house (depending on which housing area is currently congested). FCs would not be affected, since their district is instanced. If the number of FC members exceeds the capacity of one ward + annex, they could complete additional objectives to unlock a second annex, and so on, up to the maximum number of members an FC can have.

Regarding the guarantee for a player to recover their house if they are kicked from or leave an FC: this system would ensure that there are always available plots so they can relocate back into the classic wards. If the desired house size is not available while the chosen ward is not yet full, they could submit a request so that their house is automatically relocated to the desired plot as soon as one becomes available, or as soon as a new ward is opened in the desired area with the correct plot size.

In the meantime, even if they are no longer part of the FC, they would still be able to access their house in the FC district until the relocation happens. As a safety measure, a deadline of two weeks or less could be implemented during which the player must submit the relocation request if they are kicked or leave the FC, to avoid situations where a player disappears and their house remains stuck in the district for no reason. In that case, they would risk losing their house. And if the person is problematic and continues to cause issues, the FC leader could report them so that their house in the district is removed, and of course they could be banned for bad behavior.

Message to Square Enix: you are capable of doing this, and believe me, it would help prevent players from leaving the game as is currently happening (even if there are other reasons for this decline, housing remains one of the causes, in my humble opinion).

Edit: I almost forgot — the FC leader could also allow outsiders to visit the district, a bit like with Island Sanctuary, and choose who is allowed to enter or not.