A central controlled residential ventilation/heat recovery system (Zehnder Comfoair 350) cost us in 2012 almost exactly €7,000 for 134 sqm. However, not in the basement - regular use as living space does (not yet) take place here. If needed, a decentralized device is retrofitted in each of the two larger basement rooms. In new construction, the advantage is that the supply and exhaust air ducts are installed in the screed and walls - and the system creates a nice, even climate throughout the whole house - and overall there are only two holes in the exterior wall. I am not worried about the sometimes mentioned contamination of the ducts, as the first filter is located immediately after the intake opening and another one before the heat exchanger. The exhaust air vents also have filter bags, which of course must be vacuumed/replaced regularly. The central solution is also supposed to be more energy efficient. Ergo: in new construction, I would opt for a central controlled residential ventilation/heat recovery system - especially given the price difference. Best regards