We are getting more and more chickens (thanks chicken Math!) and we are looking into moving and expanding our chicken coop and pen to allow for more protected ranging for the birds. We are considering building 4 pens off the coop with separate access both inside the runs for the chickens and outside the runs for us humans. Each Pen section of the new space will be approximately 400 square feet (20 x 20) with a central common alley that allows us to get into the area to open and close off pens. Each day we plan to open one area in the morning for the foraging, then close it off at night after the birds have roosted. Only one pen will be accessed at a time but that pens door will be open all day allowing them access to both the pen and the coop for egg laying. The photo below may explain this better. Under the pen photo is a rough outline of the rotation schedule I am going to ask advice for. These will be net covered pens, completely enclosed but we want to give them a better foraging experience, decrease our feed costs, lower the amount of bugs in the area and keep the losses of birds and eggs to an absolute minimum. We are also looking to find a number of days that we can keep them in a pen before the recovery time for the grass in the "off" days or fallow time becomes critical. Right now we are thinking 4 days per pen will allow good ranging with 12 days for recovery before the next access. Each time we increase the number of days in a single area, the recovery time in the other pens goes up as well, for example if we add a day to 5 in Pen 1, the fallow days in Pens 2,3&4 goes up to 20. There will be a day however where the damage these girls can do to the pen they are in will no longer be repairable in a rotating schedule. Any one out there know what the sweet spot for range / recovery for rotation is? I am looking to know this before we get them coop moved since we will also have to bring in the grass. We live on a Lava flow so we will need to truck in dirt and sand to create the base for the grassy area for the new pens. it will take 3-4" of cinder soil then top soil then grass seed, grown to maturity before even letting them out. After all that work, we'd kind of like to make sure they don't rototiller this area into a barren oblivion in the first month. As usual, thank you for any advice or help.