Around here we wire plenty of concrete block homes.
We use what is called a romex stand off strap. It is a plastic device that is nailed alongside of a furring strip. It has grooves that the romex slides into and it keeps the space from the furring strip at 1 1/4".
We use plastic metal bracket boxes nailed to the furring strips for installing devices.
Locate the box in the hollow of the block and knock a hole in the wall. Use spray foam around the box after the job is done to seal up any air leaks. The spray foam also helps hold the box in the wall too.
For horizontal runs of nm notch the furring strips and run the wire through. Use nail plates over the romex to protect the wire from being hit by a drywall nail.
All of this pases local inspections and the cost is very reasonable both to the electrical contractor and customer.
Two man average crew can do a 1400sf house in about 2-3 days. Down here our houses don't have basements though.
