It seems like you will need some on-site professional advice. I'm no where near that, so can just add some reactions. Your home appears large and a large financial investment, so you want to keep things appropriate for the setting and not tacked on here and there. The low level by the basement is not very easy to "connect" well with the high deck so as to have the 2 spaces function really well together. The other side yard that is a higher elevation seems the most natural area for spillover from a large gathering and I would be tempted to develop that space preferentially, even if it requires some privacy screening from the front view of the property. However, if the basement room--whatever you will be making that in to--is a key action zone that will be highly related to outdoor activities, then maybe you do want to develop that walkout area more. A hot tub under that deck doesn't seem very appealing. So, to come up with the best design, you may need to flesh out your activities and traffic flow a bit more to see what is most rational from that standpoint and then factor in the $$ cost of various solutions. Also prioritize--you are trying to do this--decide if pleasant seating out of the rain is most impt, or heating in cool but clear weather, or being in hot tub, etc. I'm not sure you can build a fireplace on the deck proper, if that's what you meant.

Thanks Doug! Nice idea. Looks like you have a lifted platform from the large sliding door (which is two steps up from ground). What are you assuming is underneath it holding it up? I still need to have a platform to walk onto from the higher door (local code requires it). The higher door is about 4-5 large steps above ground.

where do you live? will the pool be closed 9 months of the year, for example? while we adore our RI pool, i wish the previous owners had built it further from the house. we have 3 months of pool and 9 months of pool cover. so if you can site yours a bit further from the house, with a patio in between, you'll enjoy your yard more. also, be 100% on top of what your local code requires as far as gates, alarms, etc. most of the 'pretty pools' shown at houzz would get a big frown from the inspector. you'll save a lot of time and a lot of money on discarded designs if you go in knowing whats what. you can not depend on contractors to know the code on pools.

so you want a deck that allows space to the window wells. (I don't know what code is for that in your state, so you'd have to check). These show ideas for decks that still allow light and egress from the window. I would advise you to do a composite decking. real wood may be cheaper, but it will need constant protection from weather and UV rays, which means painting or staining every year or two. along w/these decks, an arbor or patio cover would also be nice. and you could combine the decking material w/a hardscape depending on if you're building right on the dirt, or you want the deck up off the ground. combo of both would be nice be prepared to spend a good sum. getting all of this built isn't cheap. what you need is a patio/landscape designer to come out to your house and draw up something for you. I don't know what the big deal is worrying about the virus. everyone will be outside and has plenty of room.