Make sure you are providing adequate marking time outside. Letting dogs loose in the yard doesn't cover it. They need structured walks where they can continually mark the same areas.
Teach them to "pee" on command (check my hub out on that topic). If they then pee in the house, say "No PEE!" loudly, (or whatever term you decide on) and bring them outside until they DO pee somewhere and CALMLY praise them.
Make sure any marked spots in the house are thoroughly descented.