I would build the BIGGEST coop/run area you can/allowed 
Chicken Math is terrible and when the time come, easier to downsize than enlarge. The minimum space often recommended is 4sq ft per chicken in the coop & 10sq ft per in the run. When Hubby built my Chicken House he went 8x12x7=96sq ft, my figuring is 14sq ft per so limits me to 6. I've since had 5 Wyandottes with no squabbles but won't keep more than 4BOs as it "feels" crowded to me. Helps keep me from getting carried away 
I know HDPE ... Didn't know what it was called, Hubby used it for his boat & I used some to line my poop board. Great stuff
I do a modified DLM on clay dirt floor, girls are confined ... Toss in shavings and that's in. No leaves (here) like you all have so I basically use shavings & toss in grass clippings when I mow the lawn. Pick up the big stuff & they mix it up scratching. Just keep adding more shavings as needed, cushy makes for less chance of Bumble Foot. Maybe once or twice a year I rake out some out to fill low areas or spread in the yard, works for me.
Chicken Math is terrible and when the time come, easier to downsize than enlarge. The minimum space often recommended is 4sq ft per chicken in the coop & 10sq ft per in the run. When Hubby built my Chicken House he went 8x12x7=96sq ft, my figuring is 14sq ft per so limits me to 6. I've since had 5 Wyandottes with no squabbles but won't keep more than 4BOs as it "feels" crowded to me. Helps keep me from getting carried away I know HDPE ... Didn't know what it was called, Hubby used it for his boat & I used some to line my poop board. Great stuff
I do a modified DLM on clay dirt floor, girls are confined ... Toss in shavings and that's in. No leaves (here) like you all have so I basically use shavings & toss in grass clippings when I mow the lawn. Pick up the big stuff & they mix it up scratching. Just keep adding more shavings as needed, cushy makes for less chance of Bumble Foot. Maybe once or twice a year I rake out some out to fill low areas or spread in the yard, works for me.
