A pergola will obstruct light into the structure. What is the structure used for? How do you plan to use the deck for? Eating? Sitting? etc? Plan the activities and the furniture you'll need and draw up a floor plan. Floor plans are important outside & inside. The steps to the deck from the lawn are a little too abrupt. Needs a transition. Consider adding cement pavers to the grass, not as an extra patio but for a nicer transition design.

Thanks for all the great ideas everyone and sorry I didn't explain the polycarbonate a bit better :) This is along the lines of what we'll be using... http://www.psp.co.nz/building-brands/corrugated-sheeting/suntuf-polycarbonate The area is an absolute sun trap and we're hoping to use it as an extension to our living space, especially on rainy days! I've just sent my husband out to get a few pots of different stains for is to try - darkest brown (cedar) and a lighter brown (rustic oak) both by Cabots + the black we already have. Hopefully we can decide between one of those! I probably should have mentioned we will have black aluminium pool fencing running along the top of the second retaining wall - so the real question is do we keep everything black (pool fencing, horizontal fence, retaining walls and pergola) or do we go with a dark (or even light) brown for the pergola and retaining walls.... We just keep going around in circles at the moment. Decisions, decisions! Thanks again :)

My ex-husband and I had an issue with a large window that looked out over a sidewalk where people were constantly walking by and looking directly into our living room. We solved the problem by using window film that was one-way so we could see out but it was like a mirror if anyone tried to look in. There are other varieties as well. We still got all the sunshine and light but didn't need to worry about whether or not the neighbors could see me watching tv in my nightie on a sick day...It also meant the door to door salesmen couldn't look in and see that I was home when I didn't answer the door. http://www.gilafilms.com/en/privacy-window-film.aspx#.VOuUBS5vksQ

Looks like the palm tree look is working so I would blend that with some succulents maybe agave which can grow large and make great statement plants. Also stick with the stones.