In ZE Passivhaus Services, we use building physics skills to help our clients to deliver very low-energy buildings. Furthermore, our applied research and knowledge provide high levels of comfort. Whilst reduced energy bills and payback times are essential, most people simply want a warm, comfortable house which isn’t costing the earth to run. Passive House building certifier. We are an accredited company to assess and certifies any type of Passive House project worldwide. We also go the extra mile and can perform third-party non-destructive testing such as blower door tests, thermography, on-site U-values or ventilation systems.