06 EARTH-SHELTERED ATRIUM HOME

Some have it that, in future, our resources will run so scarce that water will become the most valuable produce on the planet. Earth, on the other hand, is still one of the most abundant materials on the planet.

Therefore, water collection, treatment and conservation, in conjunction with fine insulating properties of earth, provide the principles on which this passive solar design is founded.

Earth-sheltered buildings are best protected against extreme temperature variations, storms, earthquakes, noise and even, sadly but importantly, military air strikes.

Thus, it was with this as well as passive design principles of internal heat zoning and compact planning (double-storey structure) in mind, that this Eco-House was designed.

Owing to oval shape of the inner atrium (the court), the living room, the kitchen and dining and the bedrooms all face maximum sunlight, sometimes from the south, at other times from the east and the west. Special emphasis has been put on the utility room to accommodate major installation equipment.

The house would be ideally located in valleys and plains, and the excavated earth could easily be used to top the building. The windows oriented towards the sun attract maximum solar radiation during the cold season, but are also provided with external reflecting surfaces rigid insulating boards that are operated manually, which means that one can regulate the amount of sun needed throughout the day/year yourself, or shut them completely in the night,  to store the solar heat collected during the day, thus acting as shutters.

The entire roof area can be used vegetables garden for providing an independent food source to the homestead. In addition, an insulated vertical wind shaft with overhead skylight provides natural cross-ventilation and lighting to the living room and bedroom above. At the foot of the skylight there is an aquaponic pond that could be used to cool the airflow. This 'windcatch' can also be oriented to face the prevailing winds in the area, hence maximising natural ventilation.

Vertical gardens can also be built on slopes of bermed facades. An aquaponic pond is envisaged to provide an additional independent food source to the household. It could be used for growing a variety of vegetables and breeding fish. The vegetables, such as lettuce, consume fish waste, whilst the fish reversely feed on nutrients created by the vegetables. Thus, the household could enjoy a daily supply of fresh fish and vegetables. Vegans or vegetarians can always opt for making a hydroponic pond instead, for growing only vegetables, or the pond could be made into a simple aquarium.

Another food source can also be given by the atrium pond which, in this case, has been designed as Zen Garden, but can also be of any other design to meet your requirements. The atrium pond helps refresh the air but additionally accumulates solar heat for the building. The focal point of the garden is the environmental sculpture made of Shape Memory Alloys (SMA), which changes shape every time there is a ±10°C temperature drop or rise in one's immediate environment. This means that Nature itself would shape the sculpture and its current look, so that it does not follow any artistic style or design rationale; its form is rather determined by the local environment and climate.

Considering that the ideal location for this Eco-House would be in a plain, which are usually characterised by abundant wind power, Earth-sheltered Atrium has also optionally been provided with a stand-alone wind turbine, to produce electricity for the household. However, before you consider buying and using a wind turbine, make sure that you have adequate wind power in your surrounding area.

The wind turbine can produce enough energy to power an entire home. 'having been designed to work in harsh high wind environments. It is a two-bladed fibreglass reinforced blade that incorporates a patented side furling design that optimises output at any wind speed. Assuming a 12mph (5.4m/s) wind, the turbine will produce as much as 500 kWh per month. That is enough energy to fully power an average Eco-Home.

Masonry walls and foundations are made of recycled concrete blocks with recycled paper fillings. Recycled glass is used for floor insulation, as well. An insulating entry air-trap with sliding doors and tempered, insulated glass, provides more than adequate insulation at building entrance. All windows are sliding, double-glazed with optional beadwall installation.

Water-saving sanitaryware has been used throughout the project. All services between the floors run through a vertical shaft, provided with an access panel for ease of  inspection and maintenance.

AREA SCHEDULE

REGISTER OF WORKING DRAWINGS (PLANS)

ECOTECTURAL DESIGN FEATURES

Feature 1: Greenery

Legend:

1. Upper greenery (Roof Garden, Vegetable Garden, etc.);
   
2. Front and side greenery (e.g. creepers, climbers, etc.);
   
3. Front yard greenery;
   
4. Heat sink greenery;
   
5. Indoor greenery.

Building this EcoHouse would increase your green areas on both building axes.

Feature 2: Rainwater Collection and Treatment

Surface water was easily utilised in this EcoHouse design to reduce domestic water consumption and expenses. Being earth-sheltered, the water tank is protected from extremely low or high temperatures. The falls around the tank are profiled in such a way as to funnel stormwater into the
tank.

Collected water is then thoroughly treated for domestic consumption using a 'state-of-the-art' stormwater treatment system, processed by 100% biological means which is 100% safe for domestic use.

Feature 3: Adjustable Reflecting-Insulating Shutters

Legend:

1. Reflecting position;
   
2. Shading device position;
   
3. Precipitation protection position.

Reflective surfaces are applied to direct sunlight into building interior. They rest on insulating boards that prevent heat loss from the previously heated interior to the outside, thus acting together as both reflecting and insulating shutters, as well as shading devices.

The angle of reflection of sun's rays varies according to season, the sun's altitude, and the geographic latitude of building site. Hence, these shutters or shading devices were designed as
fully-adjustable, manually operated (i.e. using no mechanical devices), so that they can be positioned to conform to one's heating or cooling needs.

Feature 4: Reflecting-Insulating Skylights | Windcatches

Legend:

1. Sunlight reflected into the building in the morning, afternoon or the winter season;
   
2. Protection against excessive sunlight.

The windcatches used for natural cross-ventilation are combined with skylights to serve as additional natural light sources. Ideally, these skylights should be oriented to face prevailing winds and natural lighting.

The windcatches are provided with an inner reflecting surface attached to an insulating board. Thus, the former reflects sunlight into the building, while the latter prevents heat loss from the inside to the outside.

Feature 5: Suspended Ceiling for Air | Heat Exchange and Natural Ventilation

Legend:

1. Lower insulated ceiling surface;
   
2. Metallic divider;
   
3. Southern wall of the EcoHouse;
4. Northern wall of the EcoHouse;
5. Upper insulated ceiling surface.

Recycled exhaust and foul indoor air is reused to heat the cool outdoor air entering this Eco-House. The ceiling runs the length from north wall to south wall, so that the hot indoor air heats up the incoming cold air, using convection currents.

Feature 6: Domestic Food Production Using Aquaponics, Hydroponics, Aeroponics & Vegetable Gardens

The Food Chain
An ecosystem is a living community which depends on each member and its surrounding environment. The living part of an ecosystem is sometimes called a food chain. Every participant in an ecosystem has an important part to play and if one becomes more dominant than the others, the ecosystem can develop problems.

Let us start with the producers. These are living things which take the non living matter from the environment, such as minerals and gases and uses them to support life. Green plants are considered
producers and the are at the beginning of the food chain.

Next are the consumers. These living things need the producers to be their food.  Animals who eat plants are called herbivores. They are considered consumers and are next in the food chain.

Animals that eat other animals are called carnivores. They are also considered consumers and are a link farther along on the food chain since they need the herbivores for their food.

Animals and people that eat both animals and plants are called omnivores, and they are also part of the consumer piece of the ecosystem.

Finally, the last part of the ecosystem are the decomposers. These are the living things which feed off dead plants and animals, thus reducing their remains to minerals and gases again. Examples are fungi, such as mushrooms and bacteria.

This EcoHouse introduces a food chain to provide additional fresh food sources to the homestead. Bearing in mind that two-thirds of the world's population constantly face food shortages and even starvation, this ecotectural design principle provides more options and opportunities to a sustainable, and potentially, self-sufficient homestead.

Aquaponics

Aquaponics refers to any system that combines conventional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. In normal aquaculture, excretion from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is fed to a hydroponic system where the by-products are broken down by nitrifying bacteria initially into nitrites and subsequently into nitrates that are utilised by the plants as nutrients. Then, the water is recirculated back to the aquaculture system. As existing hydroponic and aquaculture farming techniques form the basis for all aquaponic systems, the size, complexity, and types of foods grown in an aquaponic system can vary as much as any system found in either distinct farming discipline.

Alternately, Vegans or Vegetarians might prefer Hydroponics or Aeroponics.

Hydroponics

Hydroponics is a subset of hydroculture, which is a method of growing plants without soil, by instead using mineral nutrient changes of the rhizosphere pH and root exudates can impact the rhizosphere biology. The nutrients used in hydroponic systems can come from an array of different sources, including (but not limited to) fish excrement, duck manure, purchased chemical fertilisers, or artificial nutrient solutions.

Plants commonly grown hydroponically on inert media include tomatoes, peppers, cucumbers, lettuces, marijuana, and model plants like Arabidopsis. Hydroponics offer many advantages, one of them being a decrease in water usage for agriculture. To grow 1 kilogram of tomatoes in intensive farming requires 400 liters of water, in hydroponics 70 liters of water, and only 20 liters of water for aeroponics. Because of the lack of water needed to grow produce, it would be possible in the future for harsh environments which do not have much accessible water (such as deserts), to be able to grow their own food.

Aeroponics

Aeroponics is the process of growing plants in an air or mist environment without the use of soil or an aggregate medium. Aeroponic culture differs from both conventional hydroponics, aquaponics, and in-vitro (plant tissue culture) growing. Unlike hydroponics, which uses a liquid nutrient solution as a growing medium and essential minerals to sustain plant growth; or aquaponics which uses water and fish waste, aeroponics is conducted without a growing medium.
It is sometimes considered a type of hydroponics, since water is used in aeroponics to transmit nutrients.

Vegetable Gardens and Vegetable Rooftop Gardens

A vegetable garden is a garden that exists to grow vegetables and other plants useful for human consumption, in contrast to a flower garden that exists for aesthetic purposes. It is a small-scale form of vegetable growing. A vegetable garden typically includes a compost heap and several compartments of land, intended to grow one or two types of plant in each plot. Compartments may also be divided into rows with an assortment of vegetables grown in the different rows.

With worsening economic conditions and increased interest in organic and sustainable living, many people are turning to vegetable gardening as a supplement to their family's diet. Food grown in this manner consumes little, if any, fuel for shipping or maintenance, and the grower can be sure of what exactly was used to grow it.

Subject to climatic conditions, sunlight and irrigation requirements, there are many crops that can be grown in a vegetable garden with very little intervention and if the following conditions are met:

1. Provide nutritious soil;
2. Keep the soil moist (not drenched or claggy);
3. Provide plenty of sublight;
4. Protect from pests.

Accordingly, some of the fastest growing vegetables that are sure to keep your dining table full of nutritious treats, are green onions (21 days), lettuce (30 days), spinach (30 days), kale (30 days), turnips (30 to 55 days), beets (35 to 60 days), zucchini (40 to 50 days), 'radishes (21 days), scallions (21 days), sunflower shoots (12 days), tatsoi (25 days), arugula (30 days), bok choy (30 to 45 days), bush beans (40 to 55 days), broccoli rabe (40 to 60 days), Swiss chard (45 days), baby carrots (50 days) and cucumber (50 days).

Vertical Gardens

A vertical garden is a vertical greening typology, where a vertical built structure is intentionally covered by vegetation. Vertical gardens include a vertically applied growth medium such as soil, substitute substrate, or hydroculture felt, as well as an integrated hydration and fertigation delivery system and a growth medium supported on the vertical face of the host wall or structure.
Vertical gardens may be implanted indoors or outdoors, as freestanding installations or attached to existing host walls or structures, and applied in a variety of sizes.

Vertical gardens can be used for growing a variety of edible vegetables, such as but not limited to, chard, cherry tomatoes, dwarf cabbages, spinach, lettuces, radishes, rocket, silverbeet, small chillies, strawberries, watercress, and so forth.

Feature 7: Stand-Alone Wind Energy

Reliable, cost-effective and environmentally friendly, wind energy is the ideal power source for many applications. Wind energy systems come in many sizes, from very small micro systems, which can be mounted on a pole, to 1.5 megawatt turbines that can supply energy to the electrical grid.

Wind energy systems require a fairly constant wind. They are designed to “cut in,” or begin operating, at speeds greater than 15 km/h and “cut out” at very high wind speeds to protect themselves from damage. When calculating whether your site has enough wind energy to effectively operate a wind energy system, the average annual wind speed and the number of
days the wind is above the “cut in” point is very important.

Initially, wind energy systems tend to cost more than conventional alternatives such as gasoline generators, but over the long term they can provide inexpensive, low-maintenance power.

Wind energy systems are a very reliable and versatile technology which have been used for hundreds of years for different purposes.

Even a mini wind energy system saves electricity generated from fossil fuels or nuclear energy. In remote communities where diesel generators often supply electricity, the use of wind energy not only makes environmental sense, it makes economic sense. Larger wind energy systems can reduce reliance on expensive and greenhouse gas-producing generators.

There are several types of wind energy systems. There are stand-alone systems which provide power solely from the wind. A stand-alone system may have a method for storing energy when wind conditions are not good. Usually, batteries are  used for storage.

Feature 8: Environmental Sculpture

An environmental sculpture is one which has no fixed shape and which allows the various temperature variations through-out the day, the month and the year, to determine its look. Basically, it is a work of art with Nature as its primary artist!

The environmental sculptures featured in our Eco-Houses are made of various Shape Memory Alloys (SMA). Shape memory alloys are metals, which exhibit two very unique properties, pseudoelasticity, and the shape memory effect. Arne Olander first observed these unusual properties in 1938 (Oksuta and Wayman 1998), but not until the 1960's were any serious research advances made in the field of shape memory alloys. The most effective and widely used alloys include NiTi (Nickel - Titanium), CuZnAl, and CuAlNi. The unusual properties mentioned above are being applied to a wide variety of applications in a number of different fields, such as Aeronautical Applications, Surgical Tools and Muscle Wires.

The two unique properties described above are made possible through a solid state phase change, that is a molecular rearrangement, which occurs in the shape memory alloy. Typically, when one thinks of a phase change a solid to liquid or liquid to gas change is the first idea that comes to mind. A solid state phase change is similar in that a molecular rearrangement is occurring, but the molecules remain closely packed so that the substance remains a solid.

In most shape memory alloys, a temperature change of only about ±10°C is necessary to initiate this phase change. The two phases, which occur in shape memory alloys, are Martensite, and Austenite.

This way one can always have a different-looking sculpture in the Eco-House, reflecting the manner in which one's local weather, climate and Nature itself, are changing. Finally, one may decide to design and shape the original form of the sculpture oneself, or hire one's favourite artist for the task!