A Japanese maple would be a reasonable choice, depending on variety selected. Really no root issues with these afa paving or foundations are concerned but they dislike root disturbance so be careful how you underplant, if you do. And JM's are not the slightest bit drought tolerant so keep that in mind with your climate and any potential watering restrictions you might face.

Mineral salts can be a problem for Japanese maples in dry areas, in addition to hot and dry winds. But especially with the shade from the house you might be able to have one do fine - if there is going to be consistent irrigation, so that the site is kept moist and humid, also with regular flushing out of the root zone.

If there is a possibility of watering restrictions in a future drought period you should probably focus instead on a drought adapted tree. Might be a good idea anyway. Maybe a canyon maple (Acer saccharum subsp. grandidentatum) would work there.

https://www.bing.com/images/search?q=grandidentatum&FORM=HDRSC2

I have a big tooth or canyon maple while slow-growing the are bigger than japanese maples. T h ey also check very badly (slow down when transplanted) not easy to find depending on where you live and can be pricey. Maybe shantung maple http://bexar-tx.tamu.edu/homehort/archives-of-weekly-articles-davids-plant-of-the-week/shantung-maple/

IMO, both the big tooth/canyon and the shantung maples will get too large for this location. They grow to be full size maples - 20-40' tall and with an equal canopy spread. They will completely dominate such a small space and overwhelm the structure. If a JM not suitable - although many DO grow them throughout CA - then look to something with an equally compact scale, perhaps a shrub trained into a tree-like form.

Shantung maple can grow in all day sun in central texas. Not even the big tooth can without some leaf damage and it's a native plant stands occurring 40 minutes from my house in the hill country canyons. It would take 50 years or more to get 40 feet tall and wide If it ever did. I really doubt it would. Also, this guy in the DFW area has selected some very nice cultivated forms including dwarfs. http://www.metromaples.com/grow/ he may or not mail order

Are you set on maple? What about a dwarf-ish selection of ginkgo. Very pretty in fall albeit for a short while.

What about Tsukasa Silhouette? 18'-20' tall and only 5'-6' wide? Orange-Red Fall color.

Tsukasa Silhouette

I would LOVE to have that tree!

Mike

Mr. maple had some beautiful 3 gallon trees at their nursery when I was there the other day. I think they were $60.

I would recommend an Amur Maple or a Korean maple.

Both of those are much too large for a 10'x 10' area and are better suited to a cold weather climate rather than balmy California.