'Eco house' is generally a very vague term, but could be used as an umbrella to describe any kind of dwelling which seeks to minimise its impact on the environment, be that through incorporating sustainable building materials, renewable energy sources, low-carbon heating sources, an energy-efficient building fabric, or more. An eco house might be achieved once a house is built, for example with the addition of solar panels.
A Passivhaus, on the other hand, is a dwelling which meets a certain standard of air changes and passive heat gain, known as the Passivhaus Standard. The Passivhaus Standard requires no renewables and does not inform the type of building materials used, it only necessitates that the completed dwelling must perform to the specific airtightness levels.
Which one is right for me?
In general, building an 'eco home' depends on what you'd consider one to be. Environmentally sensitive additions such as air- or ground-source heat pumps or solar panels will make a big difference in how much energy your house consumes. If you want to build a Passivhaus, however, you must have made this clear in the design stage. The specifics regarding air quality and heat loss that affect a home's achievement of the Passivhaus Standard must be addressed in its design. Also, if you want a Passivhaus, be prepared to install a mechanical ventilation and heat recovery system (MVHR) to ensure the air in your home stays fresh.
Essentially, it depends on how rigorous you want to be. The good news is that our
timber-frame and
structural insulated panel (SIPs) build systems all achieve high levels of thermal efficiency on their own, so you'll already be saving money on energy.