The thing is, for the retrofit case ("current house") it's a different ballpark of complexity. The thing is, there's no technical question about Ph levels - ALL

The thing is, for the retrofit case ("current house") it's a different ballpark of complexity. The thing is, there's no technical question about Ph levels - ALL houses should be built to that standard. The challenge there is political. The technical challenges are in retrofit. You might find Energiesprong (http://energiesprong.nl/transitionzero/ http://energiesprong.nl/transitionzero/) of interest - basically factory manufactured walls with joinery, move to site, crane on.