With new building codes calling for higher R-vaules in the walls, most builders have moved to using 2x6 studs for exterior walls. With a R-value of 7 per inch, close cell spray foam not only meets but exceeds code in a normal construction 2x4 wall.
By using close cell spray foam in your crawl spaces it stops the cold air coming into your house through convection. Warm air rises and the cold air seeps into your house. Close cell foam is a moisture barrier so no more wet walls.
By spraying close cell foam to the underside of your roof you can condition your attic space. Your duct work and hvac won't be in extreme temperatures allowing you to save money each month in energy bills.