[=WoR=Varth]

As I said you can make a unique house ID.
f.e:

pawn Code:

new ThisIsUnique[MAX_PLAYERS];

//Somewhere in your enter command
if(IsPlayerInRangeOfPoint(playerid,3,xxx,yyy,zzz))
{
    ThisIsUnique[playerid] = 3;
    .....................
//End

//Somewhere in your exit command
if(IsPlayerInRangeOfPoint(playerid,3,xxx,yyy,zzz) && ThisIsUnique[playerid] = 3)
{
    ThisIsUnique[playerid] = 0;
    .....................