PEACEABLE to avoid strife … promote calm.
PEACEFUL means serene, tranquil. Example: the entire facility was designed to provide tenants with peaceful surroundings. It sat in the middle of rolling hills, far away from the hustle and bustle of the nearest town.
Both words are adjectives, so they can seem almost interchangeable. I tend to think of peaceful as already tranquil, while peaceable is more of an attitude one works on. It suggests a bit more energy.