Thanks for the feedback tsudhonimh. Regarding the two tan walls. They are actually sandstone block walls that I built myself and when they and the rock is clean they are actually very similar in colour. See attached picture to give you a bit of an idea of a quick clean of the sandstone. Having said that the top wall is not structural and could be removed if it didn't fit the bigger picture I come up with, however the reason it was built was to keep the dirt from falling down the rock every time it rained and also to make it look somewhat more tidy. It is also somewhat of a railing as there is a dirt walkway and then some steps to get to the top rock. I have toyed with the idea of getting rid of all the dirt, surprisingly there is a fair bit of it and due to the weather in Sydney, most plants as well as weeds grow really quickly. I currently find myself about once a month removing weeds, which grow to about two feet a month in height specially in the spring/summer times. I do agree there are a number of somewhat flat areas, and I have been toying with the idea of multi-level terracing with a nice entertainment area. From the top rock I have a view of the city and the nice Australian weather means that we do spend a lot of time outdoors. I was hoping not to just do a boring timber balcony and the recommendation of John Lautner by makeArchitecture in the comment above has helped come up with some interesting alternatives. We have been looking at native plant options, we have quiet a few options for the area we are in and a lot of them such as the aloe vera and the other spicky plants you can currently see grow with no maintenance required except for some occasional trimming. Thanks for the suggestion to describe the garden as "rock garden" or "alpine garden" as that yielded some interesting results when goggling. I have also attached a photo of the house from the backyard to give you an idea of what the existing building looks like. We are currently planning on painting it white, as we have gotten some good ideas for similar barn style house on the Houzz site. This has definitely been beneficial feedback as sometimes it feels a bit overwhelming as it it not the standard backyard. I really wanted to have some ideas of direction before getting a professional to come in and design what the end product should look like as a whole. After I have that I can determine what I do myself and what I get a professional to do.

Hi Richard The first thing to check then is what the rules are about putting anything on that roof. A deck there will have limits to avoid overlooking, and multi-story, issues with the neighbours (I have first-hand experience of these rules :-) ), which will establish a boundary of how far you can go. Then there is the fundamental structural question of what you can put on there. Then there's the question of what you can afford... For me, a simple and cheap option would be to put some tall plants/planter boxes toward the far edges of the roof, tiering to lower plants at the front. I'd take away the plants in front of the stairs at the garage, and have smaller/narrower plants up against that garage window wall to hide it, and also away from the side steps from your upper level. That makes the roof part of the garden view, and maximises the terrace area (remove encroaching plants), and hints at 'more' around the corner, down the steps. With a bit more money and appropriate permission, a deck on the roof gives you another whole space to play with. You'd have to work out where the best access to that roof deck would rise from, without losing too much of your current paved area. Connie's idea for a bridge could work well, but would seem to interfere with the access to the current paved area? With a lot more money, permission and some engineering, I'd be really tempted to build a deck on that roof and extend it full width right back to the house, at the same level as your door/windows! That way you bury the garage (and small terrace) under a much larger area, giving you heaps of options for creating spaces. You can use the old terrace then for storage (e.g. gardening materials always take up space, and more garden = more materials; compost heaps, worms, bikes, ...). Even if you can't take the deck all the way to the front/side of the garage, you can still create a whole new area there. And you can surround it with plants even if you can't build to the edges. I love spending other people's money :-)

Analysis first, then plan, as Tookoo recommends. Use native plants, as neotoma recommends. Get specific plant recommendations locally, as Terri & sgelade recommend. Here is my two cents worth, for the shortterm. a. Remove and stockpile the lawn edging and most of the mulch back against the fences. b. Take a can of spray paint, or a bundle of surveyor's flag, and mark the largest circular or curved form that will fit within the fenced areas, no matter where the trees stand (inside or outside of the line) to form the temporary edge of your lawn area. See if the entire family agrees on the alignment or just do what looks best to you as the Senior Gardener. c. Add the wood edging to the new edge, or, it will look a lot better if the edge is not visible, using a steel edge whose top edge is down just above the grass roots and no longer visible, and not an impediment to the lawn mower. (when you form the plant beds, you will dig down a couple inches at the edge, where it meets the steel, and then slope the bed up from there, and the mulch will be contained at the level of the lawn, beyond) My recommendation, after you call in your landscape advisor, is to fill the beds totally with ground cover, beneath the shrubs, so no mulch will be seen after the two years of plant growth, using only a finer textured mulch which will become part of the soil bed. (Maybe the bark mulch will smell good in your new fire pit, along with the wood edging.) d. Plant the entire area with grass seed or sod and enjoy the beauty. The curved edge will make the space appear and feel larger and will decrease the maintenance of the smaller bed areas. On the subject of tree placement: analyse first, then plan. Look at all the views beyond your fenceline from all windows of the house, the living/ dining areas, all the bedrooms, to enhance the good views and to block the big, the bad, and the ugly. The large trees on your list will block views from the upper windows, The small horizontally branched trees will be a piece of sculpture in your downstairs view throughout the year, while their flowering and fragrance yet another reason to be alive. For instance, if you have an attractive small tree that has attractive flowers and foliage, PLUS has attractive bark color and has a sculptural quality in the off-season, you won't have to visit the museum quite as often, with a sculpture garden right out your window.

Perhaps some useful information to be found here https://thesensiblegardener.com/lawn_drainage.html aerating the lawn and select an appropriate area(s) to create a garden bed of plants happy to have wet feet. You would need to prepare the soil with gypsum/compost to break up the clay first. Enjoy your beautiful sunset after a hard day digging...