Use the engineered stone, but make an easily removeable cover.

Or, get soapstone. Soapstone is impervious to anything and everything. It needs no sealing, and won’t stain or etch, or fade in sunlight. And, soapstone is not affected by heat.

Get a hard variety, like Stormy Black or Belvedere (which we have), and scratching won’t be an issue. For a bar area as you are describing, you won’t need a whole slab…a remnant piece should suffice.

Granite has been in the sun for 1000s of years not going to change in the sun now. Use granite in the kitchen and outside , a no brainer why fake plastic stone ever is a mystery to me.How exactly is this counter attached to the home as mentioned you can't do one piece form the inside to the outside so make sure what you are doing is to code and seals up properly when not in use.

Why would the sun damage granite? It's ROCK for goodness sake.

I am a fabricator. Direct sun exposure will damage quartz in just a few weeks. Most natural stones with not fade or degrade. However, there are some stones that have been resined and/or dyed at the factory that could change color over time. As long as you pick a stone that hasn't been treated it will keep its original look indefinitely.

since no way you can match the quartz inside, use wood. rustic reclaimed kind. anything else that "resembles" a stone yet not identical will make the look contrite, tedious and cheap. go for contrast in both color and texture!

ps, if you have a piece of statement/heirloom furniture (as shown in the pic) in your kitchen area, get a piece of wood that is in the color consistent with the furniture - i am not talking matchy marchy here, but consistent, coherent "echo". it will tie the whole space together.

Corian is UV resistant, has less thermal conductivity, and has a line that looks like wood. That would be the top choice.

Be sure that the window in question is high quality, fully seals, and doesn't invite in insects in addition to the heat and cold. It is hard to have a drive through window with window screens.

I would do it all in a real stone. Note what GCS says about stones with resins. Don't get those. :)

I hope you are in southern CA, because that is the only geographic area that this type of design makes sense ... except if that window faces west!

We had a granite outdoor counter when we lived in Los Angeles. It was exposed to west and south sun for 7 years and we had no issues with it. I do suggest that you do not do a built up edge, because that is were you can get a failure if the correct outdoor/UV resistant glue isn't used.

Granite is not a problem outdoors. Neither is quartzITE. I have quartzite on my outdoor grill area.

"Granite has been in the sun for 1000s of years not going to change in the sun now."

Granite that has been in the sun for 1000s of years hasn't been resinated like most of the natural stone sold in slabs for countertops. Sunlight will destroy the resin in the stone top, just not as quickly as engineered stone. Resinated granite is a problem outdoors.

And if you want to see granite self-destruct outside, let a fabricator use his cheap polyester adhesive to build up the edges:

I passed on that repair. With as cheaply as the stoners work, it was more cost effective to replace the top.

An iron console with a soap stone top just below counter and window elevation, and hand it out. !

Why make it hard : ) and Easy to make go away at the same time. It will only have to make sense with the patio. Unless you are a restaurant ;)