The trees will shade the house in the summer.

And it’s really NOT necessary except in special cases, like over new drywall or stains, going from a glossier sheen to a duller sheen, or before going from a darker color to a drastically lighter one.

Value what you get" - Warren Buffett"Someone's sitting in the shade today because someone planted a tree a long time ago." - Warren Buffett"Your alive.

A darker grey would be more tasteful. 

Darker hard wood floors.

The numbers are almost always favourable in CA so it would be other reasons like aesthetics or some type of prevention like shading that would make solar non-viable.

Are there shade trees?

I like your cool shades in your profile pic. 

Do you have a south facing roof with minimal obstructions or shading? 

Can this just be a shade structure with a canopy, or does it need to have a roof, side walls, and a door?