You have much to consider when designing and building a new energy-efficient house, and it can be a challenge. However, recent technological improvements in building elements and construction techniques also allow most modern energy saving ideas to be seamlessly integrated into house designs while improving comfort, health, or aesthetics. And even though some energy-efficient features are expensive, there are others that many home buyers can afford. While design costs, options, and styles vary, most energy-efficient homes have some basic elements in common: a well constructed and tightly sealed thermal envelope; controlled ventilation; properly sized, high-efficiency heating and cooling systems; and energy-efficient doors, windows, and appliances.