Am I correct in making the assumption that you are referring to an HOA's common areas? I'm not going to bother trotting out a resume, but will try to help by giving you a few points to consider. The cost of the plants is a minor portion of the expense of a landscape renovation. The budget bulk is going to go to labor, materials to convert the irrigation system, the landscape maintenance the installers will be in charge of during the plant replacement period, etc. If you plan to install in-house from a designer's plan, are the persons responsible for that task sufficiently knowledgeable in all of the necessary skill areas? Who is currently contracted for your landscape maintenance? If they are a full service company, they might be the best source for installation and irrigation conversion. But check thoroughly--a verbal "Oh, yeah. We can do that." is not sufficient. Also learn if the maintenance company will be able to properly care for the drought resistant plants. What is the current style of landscape and maintenance? Drought resistant landscapes are better maintained using selective pruning techniques rather than the common practice of taking hedgers and shaping everything into balls and squares, for example. Actually all non-formal landscapes are best selectively pruned, IMO, but that is a different thread. ;) It really is impossible to judge the suitability of plants without knowing, at minimum, where you are located. Even then, an on-site evaluation is really necessary to put together a working design. There may be portions of the landscape that would be suitable for xeriscaping, without compromising the overall lush look. What is behind your association's interest in the renovation? Is it time for a plant renovation and you decided to check into converting lawn areas to reduce water requirements? Water bill sticker shock? The why is important, especially because of your budget concerns. If a full renovation is beyond your financial scope, there may be other ways to evaluate and reduce expenses (drip and micro-spray irrigation, different horticultural practices, etc.). Or the renovation can be done in phases. My husband would be my source for suitable companies that would be interested and available should you want to progress to a project consultation or bids. It does not sound as if you are at that point yet. An idea of the scope and budget would be necessary starting details.

I live here in SCV but unfortunately I drive out of the valley for work. There is no definate answer really on thinning it. It depends on how thick it is but I meant maybe thinout each plant. Proper maintenance is key. Some perennials should be pruned 1/3 or half to stay nice at least every other year. Your gardeners are most likely just a mow and blow crew and they charge extra for pruning etc and usually do it once or twice a year. But I'm no landscaper. Pick up a Western Garden Book and another great book is Pat Welsh's Southern California Gardening. Since its gonna be so hot spend the day at Barnes and Nobles reading. There are tons of websites on socal gardening, plants etc also. Google for them you'll find tons of info and more links to more sites etc. Here's an easy one to start with: bewaterwise.com another for natives is laspilitas.com

In order to get help, your property needs to be better understood than the above pictures allow. I suggest you line up with an axis that runs roughly through the center of the house and take a contiguous, slightly overlapping set of photos that pan across the property. I drew a sketch to help explain what I mean. Since I'm rough guessing and inaccurately drawing the layout, take it with a grain of salt and adjust for real life conditions. Since the patio is elevated, the camera needs to be high up. I suggest taking the pictures while standing on a step ladder or from the bed of a pickup truck. Try to take sharp, well lit photos.

There seem to be a lot of one-of-a-kind things in the front yard that aren't working together as a team. I would have less variety, but bigger, bolder, fewer things. I would ditch the bed that's between the driveway and entrance in favor of expanding beds off of each corner of the house. I'm showing palms in the beds off of the house corners. But it doesn't have to be palms. It could be another type of tree cluster or multi-trunk. Don't know what to tell you about the trees in the front yard. We can't see them completely, but they seem to be misshapen or oddly shaped. Not sure if they are contributing in a positive way. Not sure if they can be made to do that.