Whatever you do, don't put rocks in them :) They will just take up space and reduce the space available for materials that will break down and produce nutrients. I know it is hard when you have limited money with which to fill raised beds, and I always have the same concerns about the "wood" compost, but I am filling some new beds myself and have a sort of method that is working out for me. It is based on the newer method of raised beds called "hugelkultur." I have a couple new 4x8 beds that are 12" deep. The "soil" they sit upon is really "fill"--gravel and sandy sterile dirt put there when the house was built I guess. So it is hard and not useful for gardening, but will drain fairly quickly. I built a bed, then I dig down into the rocky "fill" inside the box another 12" below grade (this bed will be for veggies with large root systems eventually). Then I filled that space with pruning wood from an old apple tree I have, stomp it down and fill it again and stomp it down, so there is an almost 12" deep layer of wood. building the bed and part of the pruned wood I will fill it with This is the second mass of wood before being stomped down Ready for the next layers After that I covered the wood with a layer of grass clippings I don't have photos for the other layers, but then I added a layer of horse manure and alder sawdust. The horse manure is from a neighbor (look on craigslist under "free" or "farm and garden") and is not completely "finished" composting and neither is the sawdust, but it doesn't have any manure or ammonia smell anymore. I added some compost from my own pile, but that isn't completely composted either. The top layer is only a few inches of whatever *good* soil I can scrape together--usually a mix of peat, old container mix, vermiculite, etc. Then I add amendments (= fertilizers) that I buy in bulk by the pound by the local eco-groovy farm and garden store: a nitrogen (N) source like fishmeal, bloodmeal, cottonseed meal, bat guano, or alfalfa dust; a phosphorus (P) source like bonemeal or soft rock phosphate; a potassium (K) source like greensand, and other rock dusts, kelp meal or whatever for micronutrients and minerals. The best "top layer" if you had nothing to work with would probably be a mix of purchased material , if you had the money, like a good compost mix, peat or coir peat, and something for drainage like perlite or rice hulls or vermiculite. Plus amendments for N, P, K, and micronutrients as mentioned above. A little goes a long way. Extravagances if you had the money might be worm castings, biochar, or some really nice bagged planting mix with compost. Filling a 12-inch deep 4x8 bed takes a full yard of soil, so it is too expensive for me to buy that amount of good growing mix at the moment. The wood acts as a water reservoir as it rots and gradually holds more and more water after the winter rainy system and gradually composts down there. It also probably has air down there that helps. The grass clippings and manure are both high in nitrogen that will help balance out the carbon in the wood to compost down. I honestly didn't think I would grow much in this bed in the same month I filled it, because there was only a few inches of soil before the more unfinished materials below, but I planted fast-growing green veg in the cabbage family that like high nitrogen in it: bok choy, broccoli raab, kale, and mustard greens. These are absolutely thriving--here it is 35 days later and this is after I have been eating a lot of the greens already: Only the 4 plants in the far back corner were planted as starts. The rest were all directly seeded into the bed. I estimate I have eaten at least twice as many greens from this bed already as you see presently, by harvesting/thinning plants and cutting leaves from plants as the babies sown in between the rows start needing sun. I could actually have five productive rows in here and probably eat greens every day or two and they would be replacing that growth almost at the same rate. These plants in the cabbage family can be harvested only about 35 days after planting from seed--super productive and super healthy either raw or in stir-fries or added to pastas, etc. The more bitter ones, like broccoli raab and mustards (Brassica rapa) are very yummy when quickly sauteed with chopped garlic and some olive oil, a little squirt of lemon after, maybe some chopped nuts, and added to pasta or eaten alone like that. Here is what the bed looks like 24 hours of the day apart from when I water it, using just black poly pipe from Lowes or Home Depot for hoops If it's not covered, cabbage family plants here get decimated by the little green worms that come from the white cabbage butterflies. Aaaand, I'm going to do a second bed like this and plant with non-cabbage green veg: lettuce, chard, orach, spinach, cilantro, and basil. It won't have to be covered for the worms, but will be covered the same to protect from deer. This works as a mini-hoophouse and can be made warmer with perforated clear light plastic row cover, or for overwintering greens can be covered with greenhouse film purchased by the foot. My tomatoes this year are going into large black plastic nursery pots, with a bottom layer of rocks for drainage and to fill up extra space that the tomato roots probably won't need. Maybe a layer of mesh over the rocks for easily removing later. Tomatoes take a huge amount of raised bed space and the soil between is pretty much wasted in terms of producing green edible food. That's why I usually do them in pots or grow bags. I'm trying to do whatever is most efficient use of space for producing the most food, and the cheapest right now. Any of the 6" deep beds would be perfect for strawberries--delicious, superfood, produce all summer into fall, probably enough to feed you a meal every day. I am expanding my strawberries yet again this year. Lots of production, just like the brassica greens and non-brassica greens, and the tomatoes once they are producing.

Those actually look like snap-togther decking tiles (seen here). These are not intended to be set on grade (or bare soil) but rather as a permeable covering for an older deck or patio surface. LIke any wood product they will rot, collect moisture and discolor when in direct contact with the ground. I'd agree with Yard about removing them and then using a more durable surface - it could be concrete as suggested but could just as well be gravel or manufactured pavers, properly set on a prepared level surface.

Pool? Looks like you could do an above ground that’s level with your patio. If not that I’m a big BBQ fan and that looks like a nice area to setup an outdoor kitchen area with your preference of tools (while I’d love to have a nice big offset smoker there’s a wide range of things to consider... pizza oven if you have the interest and energy!). Having a fridge or sink in your outdoor cook area is really nice Outdoor theatre sounds like a cool idea to me as well, although if it was me I imagine I would end up not getting enough use out of it If none of these maybe just reclaim some of your grass area, maybe bring in some fill and rail road ties and make the step down a little less. Nice to have more space to throw a ball or play a yard game

Before you start to spend money, even on a plan, think about how you want to use your space and what works or doesn't work now. A two-level living area (deck above, patio below) might not be your best bet because you lose the flexibility to move things around. Right now I see your outdoor "dining room" on the deck, your outdoor "kitchen" (grill) on the lower patio area, and I don't see a "living room" at all. Where would these outdoor rooms work best in your new plan? I agree with the poster above that is is highly unlikely that you will be able to build a 3 season room on the existing deck. Where are the doors to the outside from your house? Consider enlarging your existing deck instead of adding patio. I have a very large deck and love it. Instead of 2 small outdoor rooms I have one large one. I have lots of flexibility on where to place furniture depending on whether I am entertaining a crowd or just the family. As far as a cover for the patio, because I planted a tree just a few feet from the patio on the west side, I have shade there in the hot late afternoon, and a wonderful feeling of cool shelter. I put a small 10' x 10' metal gazebo on one corner for privacy from the neighbours' upstairs windows, and the gazebo cover keeps the dining table clean. You could do that now on your existing patio. As far as vegetables, consider grow bags that you fill with good soil and can place in the sunniest parts of your yard. https://www.bobvila.com/articles/grow-bags/