In 1976 I first used an old metal garden tool shed (8 x8 ft.)and a small child's playhouse(8 x8 ft.) for my first flock at my own first home. It was in the shade all day and  worked for a few years before it rusted out too much. The plywood playhouse worked for 19 years, but was small (short!)and difficult to clean. A purpose built coop of weather resistant and sturdy construction is always to be preferred, but a lot of ways to improvise or save were the only way possible to have chickens back then for me. poverty is the inspiration for many good ideas. But, do the best you can, to  make a safe, dry, secure and comfortable coop for your birds! Being able to stand up straight while cleaning out the coop is a big plus! Remember chicken wire is for keeping chickens in, not predators out! Heat may kill or stress out your bird just as frigid temps and snow might. Provide shade, shade, shade and did I mention shade? Location should be in a well drained area as well. Build on a concrete pad or bury wire around your coop and run if possible to prevent tragic losses from possibly occurring from animals digging under the fence/walls. Most of all, observe your birds daily! I built a small  coop with outside egg collection 26 years ago, still too small, (handled 12 hens)but nice. I thought it nice to not have to hinge the roof or stoop to collect eggs in the 6 ft. tall structure. Later standing in the cold rain and snow collecting eggs, I decided my next coop would be a full stand up deal! Also, one that allowed me to collect eggs out of the weather! I gave that compact coop(a larger old coop was too  deteriorated to  save) away about 4 years ago when I got sick and was overwhelmed and couldn't take care of all my livestock. I am happy to not have it, because I might put it to use! Good luck to  young newbies and old broke dirt dobbers (like me), who have to stretch a Dollar$ or invent and adapt! Just keep trying to improve until your time is up!