Hello my friend,

what you have there appears to be a Desert Spiny Lizard, Sceloporus magister. They enjoy living near people, on their houses and such so they can harvest the bounty of insects there. They do a good job of keeping bugs down if you don't mind him on your house.

one other thought,
It could be a clark's spiny lizard, sceloporus clarkii.
They're similar, but I'm fairly sure its a desert Spiny.

hope that helps,

-Phil