Sustainable architecture seeks to minimize the negative environmental impact of buildings through efficient and moderate use of materials, energy, and space. It takes a conscious approach to energy and ecological conservation in building design. The goal is to ensure current actions do not inhibit future opportunities. Key techniques include optimizing building orientation, insulation, passive solar design, and active solar devices to reduce energy needs and capture renewable sources. Proper siting and design of buildings and renewable systems like solar panels and wind turbines can maximize energy efficiency and production. However, standards for quantifying sustainability of building materials remain inconsistent and complex.

1. Sustainablearchitecture
Sustainable architecture is architecture that seeks to minimize the negative environmental impact
of buildings by efficiency and moderation in the use of materials, energy, and development space.
Sustainable architecture uses a conscious approach to energy and ecological conservation in the
design of the built environment.[1]
The idea of sustainability, or ecological design, is to ensure that our actions and decisions today do
not inhibit the opportunities of future generations.[2]
Energy efficiency over the entire life cycle of a building is the single most important goal of
sustainable architecture. Architects use many different techniques to reduce the energy needs of
buildings and increase their ability to capture or generate their own energy.
Heating, ventilation and cooling system efficiency[edit]
The most important and cost-effective element of an efficient heating, ventilating, and air
conditioning (HVAC) system is a well-insulated building. A more efficient building requires less heat
generating or dissipating power, but may require more ventilation capacity to expelpolluted indoor
air.
Significant amounts of energy are flushed out of buildings in the water, air and compost streams. Off
the shelf, on-site energy recycling technologies can effectively recapture energy from waste hot
water and stale air and transfer that energy into incoming fresh cold water or fresh air. Recapture of
energy for uses other than gardening from compost leaving buildings requires centralized anaerobic
digesters.
HVAC systems are powered by motors. Copper, versus other metal conductors, helps to improve
the electrical energy efficiencies of motors, thereby enhancing the sustainability of electrical building
components. (For main article, see: Copper in energy-efficient motors).
Site and building orientation have some major effects on a building's HVAC efficiency.
Passive solar building design allows buildings to harness the energy of the sun efficiently without the
use of any active solar mechanisms such as photovoltaic cells or solar hot water panels.
Typically passive solar building designs incorporate materials with high thermal massthat retain heat
effectively and strong insulation that works to prevent heat escape. Low energy designs also
requires the use of solar shading, by means of awnings, blinds or shutters, to relieve the solar hea t
gain in summer and to reduce the need for artificial cooling. In addition, low energy
buildings typically have a very low surface area to volume ratio to minimize heat loss. This means
that sprawling multi-winged building designs (often thought to look more "organic") are often avoided
in favor of more centralized structures. Traditional cold climate buildings such
as American colonial saltbox designs provide a good historical model for centralized heat efficiency
in a small-scale building.

2. Solar panels[edit]
Main article: Solar PV
Active solar devices such as photovoltaic solar panels help to provide sustainable electricity for any
use. Electrical output of a solar panel is dependent on orientation, efficiency, latitude, and climate—
solar gain varies even at the same latitude. Typical efficiencies for commercially available PV panels
range from 4% to 28%. The low efficiency of certain photovoltaic panels can significantly affect the
payback period of their installation.[3] This low efficiency does not mean that solar panels are not a
viable energy alternative. In Germany for example, Solar Panels are commonly installed in
residential home construction.
Roofs are often angled toward the sun to allow photovoltaic panels to collect at maximum efficiency.
In the northern hemisphere, a true-south facing orientation maximizes yield for solar panels. If true-
south is not possible, solar panels can produce adequate energy if aligned within 30° of south.
However, at higher latitudes, winter energy yield will be significantly reduced for non-south
orientation.
To maximize efficiency in winter, the collector can be angled above horizontal Latitude +15° . To
maximize efficiency in summer, the angle should be Latitude -15°. However, for an annual maximum
production, the angle of the panel above horizontal should be equal to its latitude.
Wind turbines[edit]
Main article: Wind power
The use of undersized wind turbines in energy production in sustainable structures requires the
consideration of many factors. In considering costs, small wind systems are generally more
expensive than larger wind turbines relative to the amount of energy they produce. For small wind
turbines, maintenance costs can be a deciding factor at sites with marginal wind-harnessing
capabilities. At low-wind sites, maintenance can consume much of a small wind turbine's
revenue.[5] Wind turbines begin operating when winds reach 8 mph, achieve energy production
capacity at speeds of 32-37 mph, and shut off to avoid damage at speeds exceeding 55 mph.[5] The
energy potential of a wind turbine is proportional to the square of the length of its blades and to the
cube of the speed at which its blades spin. Though wind turbines are available that can supplement
power for a single building, because of these factors, the efficiency of the wind turbine depends
much upon the wind conditions at the building site. For these reasons, for wind turbines to be at all
efficient, they must be installed at locations that are known to receive a constant amount of wind
(with average wind speeds of more than 15 mph), rather than locations that receive wind
sporadically.[6] A small wind turbine can be installed on a roof. Installation issues then include the
strength of the roof, vibration, and the turbulence caused by the roof ledge. Small-scale rooftop wind
turbines have been known to be able to generate power from 10% to up to 25% of the electricity
required of a regular domestic household dwelling.[7] Turbines for residential scale use are usually

3. between 7 feet (2 m) to 25 feet (8 m) in diameter and produce electricity at a rate of 900 watts to
10,000 watts at their tested wind speed.[8] Building integrated wind turbine performance can be
enhanced with the addition of an aerofoil wing on top of a roof mounted turbine.[9]
Materials sustainability standards[edit]
Despite the importance of materials to overall building sustainability, quantifying and evaluating the
sustainability of building materials has proven difficult. There is little coherence in the measurement
and assessment of materials sustainability attributes, resulting in a landscape today that is littered
with hundreds of competing, inconsistent and often imprecise eco-
labels, standards and certifications. This discord has led both to confusion among consumers and
commercial purchasers and to the incorporation of inconsistent sustainability criteria in larger
building certification programs such as LEED. Various proposals have been made regarding
rationalization of the standardization landscape for sustainable building materials.[19]
What is "Sustainable Architecture?"
Eco-housing, green development, sustainable design -- environmentally sound
housing has as many names as it has definitions, but the Rocky Mountain Institute, in
its "Primer on Sustainable Building", flexibly describes this new kind of architecture
as "taking less from the Earth and giving more to people." In practice, "green"
housing varies widely. It can range from being energy efficient and using nontoxic
interior finishes to being constructed of recycled materials and completely powered by
the sun.
Green building practices offer an opportunity to create environmentally sound
and resource-efficient buildings by using an integrated approach to design. Green
buildings promote resource conservation, including energy efficiency, renewable
energy, and water conservation features; consider environmental impacts and waste
minimization; create a healthy and comfortable environment; reduce operation and
maintenance costs; and address issues such as historical preservation, access to public
transportation and other community infrastructure systems. The entire life cycle of the
building and its components is considered, as well as the economic and environmental
impact and performance.
Basically, its an environmentally friendly house!

4. Architectural Response to Sustainability
Since the Oil Embargo in the 1970’s, there has been an increased awareness in
environmental issues. Some people may look at the loss of non-renewable resources
and think automobiles are the main cause. However, that is not so. It may be
suprising to many that the majority of energy depletion comes from buildings. Half of
the non-renewable resources that are used are wasted by buildings and homes, where
as only 25% is used by automobiles (Slessor 1996, p.4). In addition, the United States
citizen uses 20 times more raw materials than the average world citizen. This shock
has hit the architectural field hard but there has been little done to remedy the
situation.
The idea of sustainable architecture is not new. As defined by Robert Berkebile, AIA,
“It is design that improves the quality of life today without diminishing it for the next
generation.”(Berkebile 1993, p.109) However, sustainable architecture is hardly ever
used. The lack of green architecture is a fault of both the client and the architect. It is
the architect's responsibility to converse to the client about sustainability, but most
firms do not have the resources in their files to produce beneficial or new ideas about
designing sustainable buildings. Also, if an architect does wish to produce a
sustainable building, the client may not want to pay the additional costs it may take to
construct, and is most the time unaware of the benefits.
The time has come to educate the clients about design issues such as “sleek does not
mean better” and “a glass wall is not better than a concrete wall.” There comes a time
when people have to stop worrying only about the exterior details and start worrying
about the internal ones, "…It is time to stop putting the fins on the Cadillac." (Slessor
1996, p.5) We as architects have valuable resources at our disposal that are more than
often over looked. In addition, as designers we must change the standards of
construction. We have to stop pulling details and other pre-fabricated building
systems out of catalogues and use our design ability to change the way architecture
runs. Architects must challenge the preconceptions behind building forms. In fact,
there is still much to learn from traditional vernacular forms.
Principles of Sustainable Architecture
The following nine ideas, as provided by the Hannover Principles of Architecture
(http://minerva.acc.virginia.edu/~arch/pub/), should be seen as a means of improving
the

5. quality of life through environmentally friendly architecture. These points are
constantly changing, so that they may adapt as our knowledge of the world evolves.
1. Insist on rights of humanity and nature to co-exist in a healthy, supportive, diverse
and sustainable condition.
2. Recognize interdependence. The elements of human design interact with and
depend
upon the natural world, with broad and diverse implications at every scale. Expand
design
considerations to recognizing even distant effects.
3. Respect relationships between spirit and matter. Consider all aspects of human
settlement including community, dwelling, industry and trade in terms of existing
and evolving connections between spiritual and material consciousness.
4. Accept responsibility for the consequences of design decisions upon human well-
being,
the viability of natural systems and their right to co-exist.
5. Create safe objects of long-term value. Do not burden future generations with
requirements for maintenance or vigilant administration of potential danger due to
the careless creation of products, processes or standards.
6. Eliminate the concept of waste. Evaluate and optimize the full life-cycle of
products and processes, to approach the state of natural systems, in which there is no
waste.
7. Rely on natural energy flows. Human designs should, like the living world,
derive their creative forces from perpetual solar income. Incorporate this energy
efficiently and safely for responsible use.
8. Understand the limitations of design. No human creation lasts forever and design
does not solve all problems. Those who create and plan should practice humility in
the face of nature. Treat nature as a model and mentor, not as an inconvenience to
be evaded or controlled.
9. Seek constant improvement by the sharing of knowledge. Encourage direct and
open communication between colleagues, patrons, manufacturers and users to link
long term sustainable considerations with ethical responsibility, and re-establish

6. the integral relationship between natural processes and human activity.