[Threshold]

pawn Код:

#define MAX_HOUSES 100 // Change this to whatever the largest number of houses you can have on your server is.

stock GetNextHouseID()
{
    new file[40];
    for(new i = 0; i < MAX_HOUSES; i++)
    {
        format(file, sizeof(file), "Server\Houses\%d.ini", i); //Replace this with whatever the link to your house files are.
        if(fexist(file)) continue;
        return i;
    }
    return -1;
}

If you don't understand, show us some of the code where you create/load and save houses. Then I will be able to fully make it for you, this is just an example of what it should look like.