Whilst we have houses for 3,4,5,6, 7 & 8 people, a large number of our houses are right next to or very near each other.
As an example, a house for 4 next to or very near another house for 5 would be ideal for a group of 9.
Similarly, a house for 6 next to or near a house for 4 would accommodate a group of 10 and so on.