Balustrade posts are required at regular intervals of 1.5m or less and must have a height of 1m above the floor. These posts can be secured by: setting them into concrete, pinning them onto existing surfaces eg. tiles or in the case of the deck, then bolting them onto the framework.
There is normally a horizontal plank attached to the posts at a height of 100mm above the floor and a handrail mounted on the top which ties the structure together. What design is chosen to fill the spaces or voids is a matter of choice.
I do not have the facilities to turn or bend wood but if these type of components are called for and supplied I can work with them.