The Passive House concept includes superinsulation, airtight construction, mechanical ventilation, passive solar where possible, elimination of most thermal bridging, and choosing home appliances, heating and ventilation units that use minimal electrical energy. A Certified designer uses the Passive House Planning Program (PHPP) to develop a computer model of the project and tests the completed house to verify that it meets the standard. Houses that meet the standards are allowed to use the term Certified Passive House.