Updated stone patio and landscaping would go a long way. Building an arbor/pergola on the patio (if you weren't doing a sun room) would be great.

I'd have a chat with a local landscape designer. You're in that "maybe this, or maybe that" stage, which is when it can be useful to have someone spend a good 45-60 minutes chatting with you, on site, and helping you work out how you'd like to live in the space (and how you likely would in reality).

Agree re: landscape designer. THe sky is really the limit here, you could do so much!

I'd also want to repaint that strange rectangle of siding a dark color so it doesn't stand out. Maybe you could split the difference on a roof with a nice pergola...

Thanks acm - it was where the elevated deck came out of the house at one point - previous owners removed it and patched it up with that - what color would you go with?

WOW Dig Doug's Design!! That looks amazing!!!