Find a local architect that can design a functional well designed solution with you. Construction costs vary geographically and the more information regarding the addition's design you can give the builder the more accurate the cost estimate will be.

It looks like you are in a planned community. I would look at your covenant/HOA documents to make sure you can even have a balcony. Your views will be into the second story bedrooms of your neighbors ... they make have a problem with that! You will also be very visible to all your neighbors when you are out on the balcony. Why do you want this balcony?

Not that it even matters, or is even your business but we want the balcony because we have a mountain view from up there. Also the house behind us is our good friend, and I happen to know that is not their bedroom window they have 18 ft ceilings in their living rooms. I asked for cost estimates and advice on what kind of contractor we would need, I did not ask for a troll to leave an unhelpful comment.

People can often give the best design advice when they know something about the context: why are you trying to accomplish something, what is going on in the area, etc. People may also be trying to save you from costly mistakes they or someone they know have made. Advice is something you may request, not demand. To ask some information isn't trolling anyone. This is an advice board. It is kind of like a buffet: take what you like and leave the rest.

The person who will know how much it will cost will be a general contractor. You will need an architect and possibly a structural engineer for plans before a contract can give you a price. Those plans may depend on whether you have (or your city has) your original building plans on file. If yes, it will save some time so they will know how to tie the structures together. If not, they may have to do some targeted investigative demolition to see how the structure that is there is put together. That's more money. (Keep in mind that you may have to completely change the roof design for that portion of the house if you choose to have the new area a covered deck. It looks like it would be difficult to tie the old roof and the new roof together. That is a lot of additional work and expense. Both on the exterior and possibly interior.)

How much labor costs, how long permits take, whether you can build in the wet season, etc. are all locally dependent and all greatly increase your costs. Do you want lighting? Do you have extra capacity in your panel or will you need an upgrade to that? Lots of pieces.

Talk to a couple of local general contractors and see if any can give you an idea of the work involved. (You will probably have to pay them a consulting or design fee for this because if they are giving you advice, they're not working for another client.)

My guess would be close to $100K, maybe more. Remodels and additions always cost more than new construction and there are tons of variables here. You will likely need foundation work, electrical, framing, roofing, drainage, finish, etc.

Good luck! It is one of the things that I would dream about and my husband would talk me out of because of the labor and expense. Can it be done? Sure. Almost anything can be done. Should it be done? Well, only you can answer that.

Chispa offers good advice. I may have missed a comment that was deleted, but if it is chispa you are accusing of being a troll, you need to get some thicker skin before starting any construction project. Projects go a lot smoother when the client is pleasant.