Well, you probably could let them wander as long as it is safe for them. Sometimes it is nice to contain them to certain areas because of poop

and they eat everything in sight. Husband's get fussy about those sorts of things, lol. So, maybe a goal could be to put a gate from fence to house.
How old are your girls? If chicks you will need to keep them very safe and a HD coop will work for the first few months.
For the long run, the good news is we are in the tropics so you don't need a big expensive closed in coop. It can just be studs and a roof. If you want to lock them in, chicken wire and siding only to protect them from wind and rain.
I like to recycle materials and build as I go. Check craigslist. Can find some decent coops on that or used materials. Just make sure chooks are dry and safe and they won't complain. ♡ unless you get the picky variety of chickens.
Congratulations on your almost new flock and welcome to byc!!