Gardening and Horticulture - Pachysandra against house

Our house has pachysandra around most of the perimeter. It is in contact with stone foundation, stained wood shingles, or flashing at various points. Is this a bad thing? We do have occasional carpenter ant infestations in the basement, but nothing I haven't been able to handle thus far.

Should I apply an herbicide and gain a foot of space between the house and any vegetation? Should I put down some stone/gravel. How about wood chips, although that seems perhaps counterintuitive with regard to the ants?

Thanks for any guidance you guys can offer.

Plants should not touch the house. They conduct moisture to the house where there need be none. Might provide a foot path for critters, too.