You've probably seen those video consoles in home improvement stores or paint suppliers which allow you to apply different paint colours to a house photograph, to see how the colours go together and what the house will look like when painted. They work OK, but there's one big problem. The house they use in the example looks nothing like the one you want to paint.
This exercise shows you how to use Photoshop layer masks and a photograph of your own house to get the same effect. And who knows, the paint shop proprietor might even pay you to do it as a service to clients!
We'll start off with a bit of photographic tweaking and then use a variety of selection tools to select areas and convert them to adjustment layers. Then you can change to colours of your house (within limits) to your heart's content (and so minimise wasted paint!).