my family and I are first-time guinea pig owners. We have three girls and one neutered boy and they all live in the same cage together. Their cage was built by us and we have expanded it time and time again. The total length currently is a little over 9 ft with the width at about a little over 3 ft. They currently reside in my "formal" dining room and are taking up half the room. If more space is needed we will happily expand but I just need opinions. This sounds really corny, but I love those little guys and want to give them the best life they could possibly have. So to get to the point is more room needed or should they be good.
For what it's worth, you might want to look over www.guinealynx.info/my-pigs.html
Years ago I gave them a room. They kind of went from one corner that was set up for them to another corner. I had the doorway blocked off so they couldn't escape.