Ed...you really should clear this BEFORE you go out to shoot the homes. What you are proposing isn't really the best way. The builder should be responsible for this...unless he wants to pay you to go about acquiring permission. Also, you will NEED a property release. Go here to see a sample property release
The builder has to NEGOTIATE the rights with you. You own all the rights to the photographs you shoot, NOT the builder. Rights are an additional fee. Whatever you do, DO NOT sell them "all rights" just becuase they say they "want to own" the images.
Finally...there are better respurces for questions like this:
are the first 2 that come to mind...