I appreciate all of your input. Let me get into all of the details to answer all of your questions/concerns. We have lived at this residence for more than 10 years and have had the same neighbors all of those years. In response to @Virgil Carter Fine Art and @chicagoans the gray block wall is a retaining wall as the neighbor's ground is just below the top of the gray block wall. We have never had issues with drainage from the neighbors. In addition, the neighbors do not have any dogs or young children & they've always stored their trash cans closer to the front of the house, which has never been a problem over the 10+ years. Even if they did have dogs or young kids, we would welcome them all :-) And yes, @chicagoans, we're in southern CA with wonderful weather :-) The concrete slab that is currently under the grill that spawned this discussion was poured prior to the pavers being placed. I'm not positive but I think it may be approximately 12-18" deep. As for the "pavers".....these are 36"x36" units that are set in place in dirt. They are NOT poured concrete. There is a small amount of concrete on the perimeter to keep everything in place. As for each of the footings for the trellis posts, they were all quite big (see photo below). They needed to be substantial enough to pass inspection so I believe they were each approximately 2-4 feet deep and at least 4 feet wide. (forgive my estimations, I'm not a professional in this industry). Let's move on to the wall/fence/property line. As you can see in the following photos, we lived with a deteriorating fence for 10 years, assuming that it was on the neighbor's property since we were looking at the backside of the fence. However, once we begun our permitting process, they ordered a survey which revealed that the fence was actually a few feet over OUR property line. After discussions with the neighbors, we agreed to replace the fence on our property, leaving more than necessary square footage on their side, out of respect. As you can see from the new fence photos, the fence is not right on top of the block wall. Therefore, I'm curious if any of this new information changes any of your opinions on how to move forward with all of the existing information. I hope I have addressed all of the concerning comments. If I have left anything out, feel free to let me know. I appreciate all of your time, thoughts, concerns & input!

you don't say what size you want or how many. if you can use the 24x24 size, I'd buy them. so they cost $10? maybe more. have you ever DIY your own pavers? you might save $50. The cost to make all of these was about $80 and a full days work. (cost could be more if you don't own any of the supplies needed) DIY Concrete Pavers Materials: Mixing pan or wheelbarrow Concrete (get regular concrete, not quickcrete which will dry too fast for larger pavers) Wood for framing the pavers (plywood or 2 x 4s) Shovel for mixing (a flat-bottom shovel works best) Water (preferably from a hose) Concrete tools: a steel float or finishing trowel, and a diamond shaped mason trowel Drill and screws Level If you want something like this, thicker, whiter concrete, odd sizes, and a lot of them, I'd hire pros to do this. (or set the forms yourself and call in a mixing truck w/white portland cement. )

I reside in northern IL so share your wind and snow load issues. Our Pergola is smaller than you are planning. The posts are 8 x 12 on center. My footings are 12” diameter and go 54” deep. 6x6 PT posts are attached via stand-off post anchors. The posts are then cedar wrapped. My Pergola top is all 2x12 and the two outside ones are carriage bolted thru the posts. All interior ones are egg crate nested then lag screwed at each joint. Summary, i am concerned about how you will be anchoring your Pergola onto the patio.

Doesn't appear that you have space under the threshold for pavers. Have you considered digging the side landscape areas so that the mulch sits below the edge of the sidewalk? If you do so, make sure to "angle" the dirt away from the home.