Before you put concrete right up to the house wall consider how dry it will
become under the foundations. If it's clay under your house, drying out
could cause problems. Using 14mm gravel chippings where you might have
thought of using concrete will allow moisture to reach the clay and I reckon
chippings will prevent loss of moisture as well.

Regards

Ron

P.S. Prospective burglars walking on chippings will make a noise which you
might hear and that's a bonus.