Question regarding Housing

[Almagnus1]

there are some discords where ppl are selling houses and relocates, how they do it?

They're offering to give you an FC invite and leadership transfer.

It's also how you end up with an account that controls 9 houses (personal + 8 FC houses).

[Alien_Gamer]

there are some discords where ppl are selling houses and relocates, how they do it?

In the case of personal houses its usually a relocation by the second party. Doing it this way you are paying the person to vacate, then you must pay the game to purchase the plot. There is also nothing stopping a third party from relocating before the second party does so there is no guarantee the second party will be the new plot owner.
-First party vacates the plot
-Plot goes on the timer
-Second party relocates from their existing plot to the new plot and pays for the new plot.
-If second party doesn't have an existing plot then they wait and compete with other interested players to buy the plot when the timer expires.

In the case of FC houses. Doing it this way is more of a sure thing for the second party as there's no chance for a third party to take the plot. But since you can only be in one FC at a time it is an option many can't use. Further, do the effort of setting up the FC and purchasing a plot, the price for this is usually greater than a personal plot.
-First party invites second party to the FC
-First party makes second party the FC Master
-First party leaves the FC.
-Second party now owns the FC and its plot.

[Catstab]

there are some discords where ppl are selling houses and relocates, how they do it?

Relocation bypasses the hidden timer.

So your friend, about to leave the server, demolishes his house. You relocate your existing house to the empty plot, bypassing the timer.