You can check out the outdoor floor tiles like the Scala (Google Snap and Go tile) which are easy to piece additionally on the ground for a new look. ;) I saw another brand here, http://list.qoo10.sg/item/OUTDOOR-TIMBER-FLOOR-TILE-SINGAPORE-SELLER-100-AUTHENTIC-BEAUTIFUL/482453309 (not sure where this brand is from but they all work the same). They even have faux grass, stones as well as timber. Definitely easy to DIY, and you can combine different surfaces together if you want (stones and wood combo for example).

So you just want to enclose the top area to make it a place to sleep? Does it need to have a kitchen and bathroom or just a sleeping area? I am not an architect but you might want to ask more direct questions like " How can I enclose this upper floor to make it livable?". It looks like you live in a very mild climate. Perhaps you should put up wood walls with windows that match the design on the balcony panels. I am not a builder so I hope someone else has some ideas for you.

Looks to be very amenable to contemporary or even mid-century furnishings. Comment here and use Attach Images button to add pix of the patio/balcony area.

I very much agree with what Beverly said regarding adding shutters to your home. You don't have the space on either side of the windows to accommodate appropriately sized shutters. Awnings would definitely be an option. Since you're in the Caribbean, you can add color by using a brightly striped awning. One shutter option that you could consider would be a Bahama Shutter. Since they mount at the top of the windows, you wouldn't have any problem adding them if you like.