Build for 8 then and double those numbers, you'll be glad you did.We're using what I've seen as the most common guideline of 10 sqft/hen in the run (including the space under the hen house) and 4 sqft/hen in the hen house. We're building for 8 using those guidelines but starting with 4, so the girls will have plenty of room to begin with... and the idea is to increase to 6, then 8 over time, if we do at all.
Adding birds works much better with 'extra' space during integration.