Ok, let's see.
The building pointed at by the white arrow (which is on the larger side for an house) has an area of 276 px, and it is ~10px wide * ~27px long (the shape is not perfect of course, because pixel are discrete quantities).
The one with the black arrow is more typical and has an area of 188px
The one with the red arrow is smallish at 141 px.
There are others that are even much smaller, like 80px or so, but most are of within the average previously stated.

Elinore90Ec.jpg