Yay!! Quality over quantity is my motto...lol! Keep in mind that the often suggested 10 sq. ft. per bird truly is a minimum, at least in my mind. Mild mannered breeds can cope okay with that amount of space, but why shoot for minimums???
Here are my thoughts: If you guys do a lot of traveling, and someone else will be caring for your birds fairly frequently, they may not feel as comfortable about the couple of hours of free range time as you are - so make it big enough that they would be comfortable if contained for weeks on end. Personally, when I see folks using one of those 10x10 chain link dog pens as a run, I would not house more than 5-6 birds inside (although some would house 10 birds, based on minimums). Many LF breeds are about the size of a house cat (not one of those mongo house cats of course...lol). So if I try to picture 10 cats living 24/7 in a 10x10 room, it doesn't give me a good feeling.
So 16 sq. ft of run space per bird is good!! If it's possible to plan for 20 sq. ft. even better!! There is no such thing as too much space - it comes down to finances and space planning...and of course being able to build the run (if not using a dog pen set-up).
For someone who is rarely gone from home, and knows they will be able to free range quite a bit (which may be your case - 4 hrs per day is wonderful), then a smaller run is doable. But what about when the days get short and it's dark at 5:30PM?? Will they have any free range time then???
My bantam run is TINY...way too small. It wasn't way too small until two extra birds ended up in there somehow (6 silkies/d'uccles in a 44 sq. ft. run!! was built for 4 bantams). BUT...those birds are let out by 8a.m. and I don't close the run doors until they've put themselves to bed at night - so they pretty much free range all day long. And because we're on a family farm, on the rare occasion we are out of town, there are lots of "helpers" available to let the chickens out.
Our other two coops have good sized runs - one offers 15 sq. ft. per bird (and they are tiny seramas ranging in size from 9 oz up to 20 oz - don't take up much physical space but are active little things), and my "big girl" run offers over 30 sq. ft per bird. All my birds free range pretty much all day, but I didn't know that would be the case when we built our first coop/run, so we built our first one with LOTS of space.
The housing you mentioned sounds fine space-wise. We do get winter snow in my area, so I did plan from more than 4 sq. ft. per bird of housing. Of course that bantam coop I mentioned is 4x5 and houses 6 bantams, so it no longer is as spacious as it once was (well, I did PLAN for more space...lol).
Anyhow...think about your lifestyle, and plan accordingly. Have fun!!
Edited by teach1rusl - 5/29/16 at 6:37am