An Earthship Module, the extra "front face" provides an additional greenhouse and grey water treatment area, as well as a cushioning barrier from the elements.
In wintertime the temperature flux between day and night can pull excessive heat from the Earthship in regions with extremely cold weather. What this front face offers is a buffer from the temperature change between day and night, so that your living space remains more temperate throughout the year. In the summer, your house will stay cooler, in the winter your house will stay warmer.
In addition to stabilizing your comfort zone, the extra front face takes your greenhouse and greywater teatment center out of your living space, affording you options for using the proximal front face in new ways; for your breakfast table, creating art projects, dehydrating foods... or just taking a catnap.
In addition to opening up new interior living space, the extra front face provides a buffer zone to drop your boots, house the pets, and generally keep the dirt outside - a promising proposition to those who live in dusty climes.
With regards to greywater treatment, the extra front face provides the capacity to treat more water and more growing area for food. You will be amazed at how much food you can grow yourself. Fresh, organic food.
We are simply adapting our needs to the already existing activities of the planet.
Why pipe water long distances from a centralized community water system, or from an expensive well that needs significant electrical power, depletes aquifers and lowers the water table, when water fall from the sky?
Why have a corporate or political "middle man" between us and our energy needs? our vessel (home) must be designed to sail with the forces that exist beyond human control and exploitation.
An understanding of mechanical systems for most humans is limited to what is within reach of their fingertips. It is understood that when you flip a switch on the wall, a light comes on. when you turn on the faucet, hot water comes out. When you pull the handle on the toilet, it flushes. Little though is given to where the electricity comes from or what kind of nuclear waste was produced to generate it. how many of us even know where the power plant is that supplies our power. Few people ever wonder which water table is depleted to bring them water and what chemicals have been added to it. Where does the sewage go after it is flushed and which rivers and lakes are polluted by it?
Humans need comfortable temperatures, light, electricity, hot water, food, sewage treatment, etc. These necessities are all available within the framework of a certain "rhythm" in the Earthship. The more we are able to align our priorities and needs with the prevailing rhythms of the planet, the easier and less expensive (both in terms of economics and ecology) they will be to obtain.
If our lifestyles can conform more to the patterns of the planet than to our socioeconomic system, we can reduce the stress on both ourselves and the planet. This is easier said than done due to the "reality" and the "gravity" of mortgage payments, utility bills and the generally high cost of eating and living. Most of us have no choice. We have to be places at certain times looking certain ways in order to make the money needed to make those payments. However, many people have built Earthships themselves and ended up with little to no mortgage payment. They also have little or no utility bills and their ability to grow food year-round inside the Earthship has greatly affected what they have to spend on packaged, processed foods.
The condition of our planet tells us we must now begin to take responsibility for what happens beyond the reach of our fingertips. We must begin to reconsider the source of these utilities, our access to them, and how we dispose of the waste produced. The mechanical systems of the Earthship confront these issues directly. We call this direct living. Source, access and destination are all contained within the Earthship, within the reach of our fingertips. There is no mystery involved in Earthship electricity. There is no unknown source of water. There is no magical black hole that sucks up all our sewage. Instead, we work in harmony with the earth to deal with these issues - taking what it has to give us directly and giving back what it wants to receive. With this harmony ringing in our minds we evolve the Earthship Systems.