5 nesting boxes is plenty for your current needs and coop size, unless you fall victim to chicken math like many here.
I have 45 hens and 2 duck hens that share 5 nests. I have 6 young pullets in the nursery but won't add to flock til old enough. With it being winter, I get 17-26 eggs collectively, most are in 2-3 nests. I collect 2X a day, late morning and dusk. Most of my girls tend to lay between 10am and 4pm oddly. I reuse those plastic cat litter buckets (ducks prefer) and I have soda crates (approx. 11"x16") that were made into a 3 tier display shelving unit from a convenience store. I tried enclosing them on 3 sides but my girls laid eggs on the floor instead, so mine are open on all sides. I use $1 dish pans as as liners for easier cleaning and often find 2 girls in one nest with a 3rd trying to squeeze in with them. I have a main 12X10 coop that 25-30 hens, 5 roosters and 6 ducks sleep in that also houses 2 30# feeders and 1 heated 5 gal. waterer (outside water available too). I will be building an outside attached water area due to mess ducks make, it will be inclosed on 3 sides with a grated floor so I can still use a heated waterer base in freezing weather. I also have a roosting only coop with 2 roosters and the rest of my hens sleep in, there's no food or water kept in it and no nesting boxes. Every morning I watch the ones from my 2nd coop file into the main one. I have a 3rd even smaller coop for transitioning chicks so my others get used to them before going to main or if chosen, the roosting only coop. And yes, I tried getting all to roost in one coop as the blue one was my transition coop originally but some were determined to stay in it so I gave in. I don't lock up mine at night, they have doggie doors on coops and have a 54ftX40ftX4ft pen around coops. My ducks patrol at night and sleep mostly by day. Plus I have 2 brother dogs in a kennel next to their pen as a deterrent. To date I haven't had any problems with predators other than an occasional mouse or frog getting in. I also use 2 baby monitors so I can hear what's going on. Its amazing to hear all the sounds chickens make when no one's around or that my roosters sometimes will crow at 1am or 3 am for no apparent reason. We got used to the night chatter and fall asleep listening to them but the crowing will wake me up.
My main coop, side with window is storage/nursery. All materials used except lumber for frame (spent under $700) is recycled or upcycled - windows (36"x36" in rear of coop), doors, siding, metal roof and interior. Coop in background is no longer used and is getting moved to be converted into our work shed.
My roosting only coop after redoing, still needs metal roof put on.
Before of coop when new, a year later it needed a roof and nesting boxes fell apart.
Right now in my main coop I use ladder roosts but it's difficult to clean under them so I'll be replacing with several long 2x4 roosting bars this spring. Plus it'll free up more floor space.
